The best game I've seen for this is WazHack. It is free to download and play, but only to a certain depth. From there, if you want to go further, you pay for whatever type of character you want to use. If you only want to use one type of character, like barbarian, it costs 1$x. If you want to play all 8, it's 8$x.

Straight forward, you can play it to see if you like it, you can play the different characters to see if they match your play style. No other purchases needed.