There are probably some cheap games on the Apple Application store right now…
…but, because I don’t own an Apple computer, I’m not allowed to look at it.
It seems strange that there isn’t a web frontend or something that I can look at from any other type of computer. I wonder what they’ve got to hide from the non-Apple using world.
Anyway, there’s no way of me finding out what games are on special offer from a Windows PC, so short of someone buying me an iComputer, or you lot/publishers emailing me to let me know of discounts, you’re going to be on your own.
Edit: Aha! James in the comments points out that there is a web front end. Although it appears to just be a list of all games in a given category, in a seemingly random order, with no pricing details until you click on a link. Extremely close to useless without being totally useless. Brilliant work Apple.

Not entirely true, but pretty awkward regardless.
http://itunes.apple.com/gb/app/angry-birds/id403961173?mt=12
In my cynical (but Mac-owning) opinion, the pure web interface exists primarily for the benefit of search engines, which is why it’s not particularly usable.
You can use http://appshopper.com/ which lists all the apps in the app store and lets you track price cuts and free games.
App Shopper is indeed very useful. Touch arcade is too, I believe they have launched a section for this new store.
THe apps only work on a mac, so I guess they didn’t see the point in making it accessable to Windows/Linux users…
I can inform you guys that the excellent Penny Arcade games “On The Rain-Slick Precipice of Darkness”, parts I and II, are both only $3.99 in the US Mac store. Normal price is… hmm, well, I guess they’re only $4.99 now on Steam (and they’re “SteamPlay”)… but a dollar saved is a dollar earned!
Precipice of Darkness 1(Mac Store)
Precipice of Darkness 2(Mac Store)
Oh, and Osmos is $4.99 (current Steam price is $9.99):
Osmos(Mac Store)
Additionally:
Gratuitous Space Battles, $16.99 ($19.99 normally)
Chopper 2, $0.99 (will go up to $4.99 soon) (iPhone port, reviewed well but I haven’t tried it)
http://chrispederick.com/work/user-agent-switcher/
This firefox addon allows you to change the user agent, so you can mimic a mac, or an iphone, or a wii etc.