Oh, man, If I had a dollar for everytime my ex dragged my ass out of bed to do the garage sale thing on a Saturday morning…
I admit that you can find genuine bargains but mostly it is crap that people are trying to unload on you.
Mark them at or near the eBay price and think to yourself how much below that you will be willing to haggle. People will haggle on more valuable items, IME. To the extent you can, devote your attention during the sale to people looking at the more valuable items and negotiating with them. The people buying 7 paperbacks for 25 cents each don’t really need your help.
If it’s a hot day, put some cans of soda on ice and sell them. It can encourage people to stay a little longer.
As a Garage Sailor perusing ads on Friday morning, I’d expect to see single former big-ticket items like a set of golf clubs, a bicycle, a lawn mower, or large electronics like a DVD player mentioned by name.
Also, I would not expect either to use your bathroom myself, or to have my child use it.
ETA: You can get Kroger Big-K pop for 25 cents a can, and sell it for 50 cents, or a dollar if it’s hot enough and you think the traffic will bear it. To the folks who balk at the price saying, “I can get it myself for a quarter at Kroger”, you can say, “Yeah, but it’s at Kroger, and this is here.” Capitalism, baby. 
As a cough professional Garage Saler, there are two types of garage sales:
**1. People who want to get rid of crap.
- People who want to make money.**
You cannot do both. If you can, I wants to be you.
This is very true.
I’ve only hit a few sales this year and I have noticed higher prices everywhere and have delighted in watching a stream of people walk in to a variety of sales, go " meh" at the overpriced do-dads and beat up circ 1973 couch that looks like hell, and then stream right out of a sale.
When this is happening, you need to readjust your pricing structure.
Organize everything according to catagory. Xmas crap on one table. Kitchen wares on another. Books in their own bin. (Books, if you want to move them, put some ridiculously low price on them or offer .25 a book $2 for an entire bag of books. )
Clothing is a very hard thing to move. Most people are icked out at used clothing.
Put up a sign that says, " No reasonable offer refused." Only old timers and guys really get into haggling. It is so Un-American.
Put anything you don’t know how to price on this table, and make sure that the sign is clear that you reserve the right to refuse any offer given if ridiculous. And don’t hesitate to tell those people to bugger off if necessary. Tables like this are the best way to get a decent offer for any of your unusual or hard-to-price stuff. A lot of times, you’ll also make a lot more money this way because customers will make you reasonable offers that you may have not realized; some stuff is a lot more valuable to someone else than you think, and some stuff isn’t as valuable as you think it is. Make sure that anything you put on this table is either rare or in like new condition. Examples of stuff to put on this table:
[ul]
[li]artwork[/li][li]golf clubs[/li][li]expensive memorabilia[/li][li]expensive clothing items that you think that someone would actually want**[/li][li]oddball items[/li][li]gently used tools (no beat up stuff)[/ul][/li]
[sub]**You would be surprised at the crap that people will put out for used clothing; I rarely see anything in yard sales clothing-wise that I would ever buy, as it is either outdated by 20 years or is a style and size that is unique to the customer and not common in the area. [/sub]
Also: have at least $100 in change. You don’t want to scare off a customer because you can’t break a $50 on a $30 item.