I've had four breeding pairs for about two years now, I just purchased the pastel male a few months ago when I got my tax returns. The pastel will be big enough to breed in two years, and I'm going to hopefully get him to mate with two different females that year. The pastel is a co-dominant trait, meaning when I breed it to normal females about half of the offspring will still be pastels. I paid $2,500 for the pastel, mostly as an investment.
But, all in all, I just love ball pythons. They are extremely easy to care for, easy to breed, and they're friendly.