The key to getting close to the bubble/the bubble is realising that to steal the blinds, you do NOT need to go all in. 2.5x works perfectly well, and 3x can also get the job done on slightly more agressive tables. I just never understand people who suddenly go all in OOP to steal the blinds with Q10s. It is insane, especially in early position.
I think it's Elky, but it might be Jonathon little, says that you should only be going all in if 3x leave you back a stack which means you are commited, or that if you are willing to raise and then call an all in, you should be going all in to exert maximum pressure.
My own personal addition to that is that if you always 2.5x or 3x then people can't work out your range, and also if you do it with something like 1010 and get 2 other people all in you can fold marginal hands where you are clearly losing, and often dominated.
Lastly, Wizzim is spot on. The step up is massive from one to another buyin. I now play almost exclusivly $15 6 seat hyper turbo's. Although I can win at $30 ones, at $15 I can make a profit much easier and more regularly without the risk and bank roll for $30 ones. Last 7 days on $15 I am running at 47.69% ITM, while on $30 I am at 28.8%. In the past I have run at 42% at $60, but people up there adapt quickly and work out how to play you, and therefore making money is difficult in the long term.
The line between making money at the buy in above, and making more money with less risk at the lower buyin is a fine one. For me, the less risk makes the lower buy in the best option.