30 buyins? very dependant on yourself imo. There is an aweful lot of information to be found on moving up. Personally I like the idea of some tables of your existing limit and 1/2 of the next. Playing the same level your used to at the same time encourages you to play the same way, which if you are a good player at the weaker level should not be too far off the next level.

gp & gl Vinland.