Over 100 already. I've had a lot more. Nothing really limits me - other than a ready supply of food. Fortunately my local pet shop owner is a great guy and supplies me with rodents at an affordable price.
Time and space, here. I'm fascinated by my reptiles, and I spend ages enjoying each one. I don't want too many more because I wouldn't get to spend the time with them that I do (for the moment, just about three more CTS). And space - I don't do click-clacks. No judgement of those that do, it's just that I like having my little guys in pretty cages where I can see them.
I'm a strong believer that whoever said money can't buy happiness was deluded, or had no way of obtaining lots of it, so they were trying to convince themselves they didn't need it.