FUN BUT ANNOYING

Im enjoying this game except for:
1) to get green bills, you have to pay real $ for them because the only other way to get bills is to go up a level. There arent any guides to tell you HOW to level up, (It seems very random.) and some things you can only get with green bills;
2) what is the deal with XP?! I keep collecting it; but there apparently isnt anything I can do with it. A certain amount of XP should become coins.
I realize the designer is trying to make money from our frustrations; but come on!

Granny 2 Three about Green Farm, v1.0.0