Seems like lite and ad supported versions are very scarce on the iPad....if devs don't want to have trial versions they need to instill a return policy....I'm not going to pay $13 for a game if I have never tried it.
Wow... I don't know if I've ever bought a Wii game or playstation game after "trying it" first and those things are $40-$50+ Not sure why the iPhone/iPad should be any different. You either trust the app stores reviews and take a chance... or you don't buy it. How many people would buy a game... beat it in the first day or so and then return it? Sometimes you gotta take a chance on apps or be that person always wondering.
There are many devs that do a dumbed down, fewer stages in the game, etc... type app for free. Not all but many. I definitely don't see a return policy ever being implemented in the app store.