One can NEVER have too many cats.

I have a shirt with an old lady and a saying "If you know how many cats you have, you don't have enough."

I think that says it all!!!

On a more serious note, I think it all depends on what you can afford. Cats are a lifetime commitment and will need medical care at times as well as food. In my opinion, if you cannot afford vet bills, spaying/neutering and food, you have no business having a pet.