Except for the modern looking versions, all that’s in stock is the little death ray and disciplinary assurance device. 
Yeah. I acknowledge that John Carter was sort of “retro-futuristic” in some ways, but it doesn’t quite fit in with Steampunk, which is usually very rooted in a Jules Verne aesthetic, at least as a starting point.
Man, I’m really getting tired of correcting myself. The retail price is $795 but everyone knows that for watches that’s complete bullshit. Here’s a realistic price of $188 delivered. Sorry. :o
edit: GL - just saw your post so the “getting tired” part wasn’t direct at you in anyway. 
It seems to me to be a mindset, too.
IMO only: My impression of the Victorian tinkerers, inventors, and to some extant, thinkers, had an optimism about the future of industrialisation and science. Hunger, disease, and the need for war would be eliminated.
Nowadays, some people feel that industrialisation crushes the spirit, and chains man to the service of faceless, powerful megacorporations. We feel that science doesn’t answer the really important questions (“what’s it all [life] mean?” “How do I find my soul mate?” etc), and even distracts us from figuring out the answers to the deep philosophical questions. All science and technology has brought us is more efficient ways of killing each other. 
Steampunk harkens back to the age of optimism and innocence. (Obviously, there is an element of “yesteryear was better times” in this.)
I was dreading a second installment of* Avatar* because the first series was soooo good, but* Legend of Korra* really nailed it by bringing a Steampunk aesthetic to that world which played well with the more mature themes and characters.
From my outside vantage, it’s like many movements, becoming popular because it’s the combination of an esthetic and a philosophical outlook. Lots of people just like playing fancy dress-up and High Victorian is a sweet spot of interesting details and fanciness in everyday but semi-formal wear, plus it has a gothic tinge that, as mentioned, can attract the Vampire Masquarade cosplayers, too.
Other people are more attracted by the optimism and individualism; the fantasy-world where one creative inventor can create a world-changing device, while the device is still simple enough to see and feel and understand.
Thirdly, I think there’s also the esthetic of objects: Victorian era is also a sweet spot of machines that were high-tech enough to be interesting, but still hand-produced and rare enough to be made pretty. So the beautiful brass and wood and so forth are a way to, say, make a computer case that’s both appealing and clearly technological.
Finally, of course most steampunk is quasi-magical. Because you can’t, in the real world with Victorian materials, actually build steam-powered zeppelins and death rays and Captain Nemo submarines and other fun stuff. What’s the point in role-playing someone who invented a slightly more efficient telegraph receiver?
I bring you: Steely Dan!
Wikipedia is full of bullshit. Some steampunk has neither, but stuff like aether engines or phlogiston drives i.e. stuff that the Georgians or Early Victorians believed in, even if later proved false. But anyway, anyone saying you must have X to be steampunk is full of shit.
Which is weird because the Victorian Era, an era that seems popular with the steampunk crowd, lasted from 1837-1901. If you want to talk about soul crushing industrialization you would do well to look into this era. This is the era when artisans lost the fight against souless corporations, became faceless workers and when they had the temerity to strike or protest they were viciously attacked by their employers and the government.
Maybe. I still think most people’s interest in steampunk goes no further than “wow, this top hat looks really awesome with this pair of goggles on it!”
Edit: In the interest of full disclosure I admit that I really hate steampunk. Oddly enough I appreciate the work that a lot of these people put into their costumes and props. But there’s nothing meaningful behind the aesthetics.
And airships.