After having read through this thread I wanted to offer my (often wrong) feelings on the matter.
Firstly, I feel that its in bad form to caution the GM not to take action. You can already tell that the GM is bothered by players actions and, for my part at the very least, what the player is doing is not only munchkin-like but downright unrealistic. Nobody in their right mind remains homeless, carrying $25,000 in their wallet. I'm paraphrasing and slightly warping the story, but my point is still the same. The player (and all players, really) need to have the understanding that Lifestyle exists for a reason. Now, I could totally see someone having a "Squatter" lifestyle but be living with another one of the players who is eating the brunt of their presence in the face (for double costs, mind you, but whatever). I saw A4BG say that he wouldn't bog the players down with forced lifestyles (paraphrasing again, there) but honestly ... SR really loses some of its zest when money is no longer a concern.
In fact, a good friend of mine and I have argued this point until we were exhausted many times ... but why would a guy with $25,000 in his pocket and nothing to spend it on keep putting his life in danger to run? He obviously doesn't need the money and apparently holds zero value/utility to him.
Personally, when "rent" time comes around and my "squatter" and "street" lifestyle players decide not to upgrade to at least a LOW lifestyle, bad things DO start happening. At low I just play up how bad life is ... make it really suck to be where they are and hopefully convince them to reach for that "Retire rich in a mansion" mentality that so many dream of but never reach.
Btw Reaver, I've read your posts and good job! I grew up poor and fought my way up the corporate ladder to where I am today. The difference is so vast that I feel particularly qualified to comment on lower lifestyles and I found your discription of the dregs pretty accurate. Again, good post! For what its worth, I was often forced to eat portions of MRE's growing up ... and to me and my siblings those things were better than the way I might look at Olive Garden now. I would not have traded those things for ... well ... anything. It was like prime-rib for us back then. THATS poor.