RO2 is very much like cRPG. First you fail, can't kill anybody, get frustrated, etc. but later on, it gets better when you know how to play properly, and then, it get loads of fun
Another cheap games I can recommend are:
Dungeons of Dredmor. Really fun indie roguelike-game, great humor, awesome gameplay, nice catchy music, and diggles!
Just Cause 2. This game is so much fun to fool around in
Puzzle Agent. Now, if you're in to puzzles, this game is great for you! I personally loved it, the story, the game play, the art style.