I'm not finding any apps that have an initial charge either. I am finding apps that require you to pay money in order to use them, but just not install them. Netflix, for example. You can install the app for nothing... the service is just useless without an account. FreeMovies.com is another one. The Chrome app costs nothing. However, in order to actually watch movies through it, you need to pay a one time fee. Plants vs. Zombies is a free trial, but if you want the game, you need to buy it.
Where are the apps you need to pay for? I don't see anyone making them, and it's probably because they would have trouble getting people to purchase them. Not the service... the Chrome App.