There really isn't a right answer for this one, I personally like buying my ball pythons young. I enjoy raising them up into adulthood and breeding them. Others want ball pythons strictly as pets, and when I sell my ball pythons to people they want them as young as possible. Yet there is people who are looking for quick projects, and these people look for breeding size animals so they can get the quickest results. So I would say it all depends on your clientele, maybe try offering what you have and those that you don't sale hold back. I've been trying to sell three of my Mojave's from 2015 season since May. I'm not going to use them for breeding so I'll just raise them until someone buys them.