So many new players don't have the perspective of time that I and some players do. Being successful for a year or two doesn't prepare you for the real long run, unless you plan on getting out soon. Being a professional player and depending on poker for your living is much harder than anyone gives credit for. I had the easiest gig a professional could ask for, being a non-moving prop for a mid limit game in California. I would show up and start playing within an hour or two and leave after my 8 hours in the room were up. Got paid $200 a day to do this. Unlike lower level props I never had to get up and go to a lesser game. Imagine getting paid good money to play poker and still not enjoying it! I still marvel at the thought, but it is true. Poker as a hobby is so much different than poker as a living. Trying to get to a point where you decide if you are ready to move up gets real serious when you play for a living. Risk has to be heeded often, even though you might know you can beat a bigger game.
Just think of it like you would a house. You can afford a bigger nicer house according to the loan officer. The agent and the loan guy want you to buy it because it is how they put money in their pockets. Your wife wants you to buy it because she constantly whines you don't have enough space. You start to think I should buy it. But what happens if you lose your job? What happens if you can't stand your job in a year? What happens if you get a pay cut? Your flexibility is gone and your risk goes way up. You will get stressed easily and bills will seem bigger than life.
Poker is just like this. The higher risk isn't just in terms of chance to go broke, it is higher risk in terms of what it can do to affect your game. Your playing style can change, you value bet less and fold too easily sometimes. Don't tell me the money doesn't matter because it ALWAYS does. The only people for who it doesn't matter are those who really don't care about money, just the challenge. Even they at some points have to think about money and where they stand.
Just the insights I can offer from a long history of playing. I don't even play that much anymore, I burned out on the game quite a bit in the past. I can tell you these sort of academic questions about bankroll and moving up turn out to be almost trivial. The real questions to ask are you really ready for it in a sort of "360 review". Can you handle the risk, can you handle the pressure, will it make your life better? Often it won't add enough until you are so far ahead of the game the move up doesn't really affect you. And that my friends is the secret to successful gambling for profit. Be ahead of the game and the stakes enough to where money and risk don't affect you much. If you have the money to play at 80-160 or below, at which do you think you will play better at regularly, 80-160 or 30-60? You can cruise through the 30-60 game with ease and play your best nearly all the time. You won't be able to do the same at 80-160.
Myself I realized that even at the good pay for propping I wasn't getting ahead enough to justify the risks and the mental battle it created. I was good enough to beat the 15-30 or 20-40 games I played, but I wasn't way ahead of them in skills or money. So I gave it up and went back to where the stress was less: behind a desk.