I've barely gambled - I just tried out roulette a bit and thought it was cool how if you lose and then reload, it says the croupier is "checking the table for potential cheating" or something like that, and won't let you spin again for 60 seconds. I have something like 30,000 plus a load of NCR and CL money.
I've spent plenty before that, in a pretty blasé way too. For example, just randomly buying every weapon mod I see then the weapons to go with them, just for the achievement (prior to that, I'd only modded one weapon). Also, god damn it, no one told me if I kill Mr House, I won't be able to sell Snowglobes any more!
In terms of getting kicked out of casinos, is it net winnings or winnings in one go? Also, is there an easy way to earn money in Dead Money? It seems to get mentioned in such a way, so I'm just wondering.