You can learn how to play Poker for pea-nuts, here is nothing magical about how high your stakes need to be, and who determines how much is high stakes? For someone earning $10,000 a week, $100 buy-in is pocket change, whereas someone on $10 a week, 25 cents would be a small fortune.
I was playing a free-roll when it became heads up my opponent asked if we could split 50/50 because he wanted to withdraw his winnings as it was a lot of money to him, I personally didn't care if I won or lost at that point as the difference was only $5 and wouldn't buy me a coffee at Starbucks.
To him it could have possibly fed his family for a few days, I really don't know, but obviously it meant a lot to him, Money is only important to the individual playing, Phil Helmutt could win half a million Dollars in a tournament, it would be negligible to his bank balance, but that kind of money would be life changing for others.
I think that playing Poker within your Bank-roll limits, is the most sensible way to play, and even if you had $100,000 in your
bankroll I certainly wouldn't buy-in for more than 1% of it, and if I did, would it be fun to play? It is not fun, to lose money you cannot afford to lose, I have played against some really good players at low level stakes, and I have seen Bingo players at higher stakes, so really it is all down to what you can afford to lose.
If you are on a low income, stick to your limits, play sensibly, and you will still learn how to play Poker, and the only time to increase your stakes is when you are comfortable doing so.
When the fun Stops, STOP!