You earn a million pounds per day. You are married to the love of your life. Would you choose to have kids? If you do would you decide on a number of kids, e.g. 2 kids or 3 kids. Or would you want as many kids as possible considering money is not a problem. This means that you have more responsibility as a parent but you can hold your own party or a mini rave without guests.
Personally if I was rich I'd have many kids as I can because I feel as though a large family is more fun, but maybe I feel this way because I have quite a few brothers and sisters.