Yeah, totally not true. You just need a thick ... um, anyway, you don't need to be rich. You don't want to be skint, obviously, but people who flash their credit cards around only attract a certain sort of girl, i.e., ones who like men with nothing attractive about them except their credit limit.
Keeping them, I suppose, is a whole different story. There are definitely some who marry for money or security. But again, I can't see why anybody would voluntarily enter that kind of arrangement, however hot the girl is. I'd rather hook up with a 6/10 who knows how to enjoy herself even when dinner is bian dang and a beer from 7-11. The other sort tend to moan and whine like spoiled brats if life turns even slightly less than picture-perfect.
Of course, if you're talking about girls way out of one's league, looks-wise, I believe the standard method is to just pay for what you want, no beating about the bush. I'd guess it's cheaper in the long run, and amounts to much the same thing. Personally I'd rather work within my limitations.