Like everyone here's said: you get what you pay for. It's finding that compromise between budget and quality that you're after. If you're just training and you want to keep it cheap, any old paint will do (to an extent, some is just rubbish and should never have been made), but if you're sick of your paint arcing off in weird directions, breaking in your gun, or not breaking on target then you might want to look at some mid-range paint (blaze, inferno, formula 13, and the like), or if you have money falling out of your rectum buy something good like chronic.