Well, generally speaking "more power" and "cheap" don't go together well. However, here's a few ideas to get you started:
-Remove airbox lid: $ Free
-# 250 main jet to compensate for no airbox lid (a must-have): $ 5.00
-Head Mod: ~ $ 60.00
-Good used aftermarket pipe: $ 150.00
-# 300 - 320 main jet for aftermarket pipe: $ 15.00
-Uni air filter: $ 25.00
That'll give you a good start to a quicker Blaster on a budget. Then do some reading on here and your possibilities are limitless! I:I