nh. 20 buyins is fine, one more buyin isn't going to change anything

depending on how you feel about your skill level you don't necessarily have to wait for 20 buyins to move up. people seem to feel like once they 'move up' there's no turning back. If you think you can beat a level up but only have 12-15 buyins for example, take some shots and set a stop-loss and see how you do

but that's imo