I'm not to sure if you could call it a living, but as of now, online poker is my only job. I only play at
Ultimate Bet playing NL400, I have 3k that I keep in my balance at all times, and at the end of the month I cash out everything over that. It can be anywhere from 1500 to 5,000. Mostly ranging in the 2k to 3k (profit). See, when I play on UB, where I keep the vast majority of my roll, I play tighter than hell. If you ever catch me on a differnt site I have a totally differnt style of play.
As far as starting out with 1k or 1.5. I dont know, I would keep working where ever you are and then just keep adding to your roll with each paycheck until you have a sustainable amount of money that you can start off with. Playing NL25 for a living I would think would be stressfull as hell. BUT, if your just looking for a change and can afford to only live off of 1k a month. Then go for it. But grinding for a living is never a good idea.
It is definately possible for you to live off of your earnings at NL25. I know a guy that plays omaha and does just fine.