Another aviator here. I’m an instructor, so I get paid for about 90% of the flying that I do. But I pretty much plow that back into training for myself.
And I use the word “training” loosely - I can’t say that those joyrides I took in a MiG-15 were strictly necessary for my piloting skills…
Antique car restoration. You’ll pay a thousand bucks for a multi-ton piece of rusting metal.
And then you start spending money.
My last obsession was scrapbooking. It’s stunning how much money you can wrap up in paper goods. Whew!
Warhammer 40K, models, paint, brushes, glue, putty, terrain, books… all at prices no sane person could possibly find reasonable.
I guess it’s become learning about wine. The bottles of wine themselves add up, but there are a lot of other things I spend money on - gadgets, glassware, books, magazines, classes, tastings, and eventually travel. All kinds of stuff. I do work in the industry though, and expect to be involved in it one way or another for the rest of my life, so it’s a hobby I also consider as sort of an occupational education.
Shooting - Most of my competitive/carry guns are worth a couple thou, and as a hobbyist I shoot the real cheap stuff. Scopes cost about the same.
If I get back into Ham Radio, that’s kinda pricey as N9IWP mentioned, and you can’t have just one radio.
Pocket watches are a distant third, but only because there’s no way I can afford the cool ones.
My hobby is so expensive I’m not doing it anymore. Know what makes a helicopter fly? Money. It seems that if I have the time I don’t have the money. When I have the money I don’t have the time. A Robinson R-22 goes for about $200/hour wet. A Schweizer 300CB is a little more. And since I’m not current, I’ll have to fly with an instructor for several hours at whatever they’re charging nowadays. I’m thinking of getting back into fixed-wings, since they’re much less expensive. But first I need to renew my medical, get new glasses, and finish up non-flying things such as seeing to getting the MGB completed and doing home rennovations.
At least I have another hobby. Let me tell you about filmmaking… :smack:
Another pilot here - for details do a search on my username, I’ve used up lots of bandwidth on my adventures here.
Runner up - I do leatherworking.
My expensive hobby is astronomy. I’ve got two telescopes an 8" SCT and a 2.5" refractor a set of binoculars. Combine that with four cameras two DSLR’s, a digital imager and a video camera for output to the laptop. There are also things like autoguiders, autofocusers, laser pointer, lens kits, spotting scopes, mounts, extra computers, books and star charts, etc, etc. I’m also looking for another telescope now (16" trussed dobson - just don’t tell the wife yet) as well as looking into at long last getting my own dome setup which I’m hoping to outfit with a fully automated 20" reflector. And at least if I am ever made to spend the night in the dog house so to speak I’ll have fun. As it is now my wife has to lure me into bed. I’m also very thankful to live in a place that has near perfect skies for astronomy.
Recording equipment and instruments. I spend a disproportionate amount of my free money on gear. I record my band, other bands, and just really love recording good music with great equipment. Most of the stuff is vintage or can no longer be purchased new, and 99% of what is new is boutique-made, not something that can be bought down at the local guitar center.
It’s all ridiculously, comically expensive.
I just spent $1500 on a microphone. Just a single mic, no big deal. It’s a GREAT mic, but in the grand scheme of things, it’s just one more small piece.
According to my father, I am an expensive hobby or in any case, a long term investment with a low rate of return. I just remind him that I’ll be choosing his nursing home.
I must admit, I can shop like it’s a hobby but I try to avoid that. My hair is my expensive hobby. I love it so I’m always buying pretty hair clips and dyes and things like that. Also; piercings. They get costly.
Photography:
I take pictures of my oldest daughters soccer games, my younger daughters dance competitions and nature pictures (flowers, Birds, frogs and other wildlife)
Nikon D50 body, I’ve had it a little over a year and I’m already looking to upgrade. I just purchased a 200mm-500mm zoom that cost as much as the the body and 2 lenses, an 18-55mm and a 55-200mm. My current photography wish list at Amazon is just shy of $3000 and doesn’t include the new body!
Classic cars:
67 Mustang coup it’s my daily driver and I do all the work myself so the cost is usually just parts. Every year I pick one or two major things to repair or improve. This summers project is the suspension upgrade and transmission rebuild with a shift kit.
69 Thunderbird 4 door waiting in the wings. (like the one in the picture but in Seafoam Green and a lot rougher shape) 365hp from the factory 429cid ThunderJet engine. it really needs it too, its so freakin heavy.
I am an avid photographer as well, but I’m trying to be minimalistic about it at this point. I have one 35mm SLR body - a Canon Rebel that I bought used with a 35-80 mm zoom lens for $150 all together. Not bad at all, I thought. But then I had to accessorize - $30 for a tripod, $20 for a cable release, $50 for a camera bag, and around $50-60 on some second-hand but like-new filters. So we’re talking around $300 right off the bat. But THEN I wanted to get into macro photography, so splurged on an 80-300 mm zoom lens for another $150. And then, of course, I realized that the camera’s internal flash was teh sukc, so I got an external flash for yet another $30. Oh, and a new camera bag, too, because the first one I bought wouldn’t carry my shiny new telephoto lens. And then there’s all the film and developing I spend money on. Thank god I finally caved in and got that Frequent Foto membership…
And that’s all I’m gonna spend on that damn thing right now 
But, seriously, I couldn’t be happier. I’ve learned so much about photography, and have been so pleased with my photos since I started getting serious about it that the cost of getting started up doesn’t bother me now at all. And as long as I can continue to take great photos with my trusty ol’ 35mm Canon, I’ll be happy sticking with what I have for now.
Baking, particularly that I’ve become picky about the materials I use (like wanting to use good chocolate over Nestle chips). All those ingredients add up.
Scuba diving. The equipment is very expensive (my relatively inexpensive dive computer, for example, cost around $600). When I was living in Beirut, I could dive every day for about $10 per dive…but then I would get to thinking, “Hey, the Red Sea isn’t too far away, and the diving there is so much better.” Traveling to diving resorts is expensive.
Punting.
Apart from that, books.
Golf and scotch.
There is a driver I want that retails around $500. I think I need to be a better golfer before I get that. Or wait a little while and find a used one.
Typical price on singles malts we’ve been buying lately range from $60-$90 bucks.
I’m a knitter too.
Like the others have said, it doesn’t have to be expensive, but it certainly can be. I tend to prefer soft wools & other animal fibers, which tend to be more expensive than synthetics like acrylic. Even with online stores like Elann & Knitpicks (which sell good yarns at cheaper prices), I’ll still end up spending an average of $70 to make a sweater for myself - and I wear a small size.
I just got a book & have plans to make a hoodie from it - if I were to use the yarn the pattern calls for (I won’t be), it would cost me nearly $200.
My previous hobby was High Power Rocketry. That is a hobby where you literally watch your money go up in smoke.
Currently I am into ham radio. It has been expensive building up a decent station but at the moment I am fairly satisfied with what I’ve got.
My wife’s hobby is photography though.
AHoosierMama, I’m glad I’m not the only golfer here.
I’ve been on hiatus from the game for a few years, but when I was playing a lot, it was easily $200 to $300 a week (minimum), from early spring to late fall. Many weeks it was more. Much more. Clubs are expensive, ranging into hundreds of dollars for a single driver or wedge, or etc. And golf balls? Forget it. Once you’ve gotten good enough at the game that you’re not losing a dozen balls every round, you realize that the balls need to be refreshed anyways, after a few holes, so you still use a dozen a round (at least in my opinion/experience). There’s a clubhouse full of useful (and useless) doo-dads, cleats, wet gear, etc. Then you might want lessons, and of course you’ll spend money at the driving range to practice. And so on.
Then, of course, there’s the 19th hole.
A “perfect day” of golfing went like this: 7:15 am tee time, so grab a coffee and egg sandwich on the way to the Club (cha-ching), pay for the round, rent a cart, buy some balls, “Hey, that’s a pretty sharp Far Corner Golf Club shirt. $35? I’ll take it.”, couple bottles of water, granola bar, smokes (I’ve since quit), “Ready?”, “Yup.” (cha-ching, cha-ching). So now it’s 7:05, and I’ve already spent around $125-$150 and I haven’t even climbed into cart.
Technically, you’re expected to play 18 holes in 4 hours. It’s more like 4 1/2, so we would finish up right before lunch time. Back to the clubhouse for a hot dog (maybe a burger) and a couple beers. (cha-ching).
“Boy, I was really hitten 'em good. Wanna see if we can get out for another 9?”
“Another 9? Why not another 18?”
“Sure. Let’s go to Outback for a steak on the way home.”
(cha-ching)
And so on.
