I think it depends on how comfortable you are with having a 6' snake on your shoulders. I have a baby red tail and so far he isn't any more difficult to keep than my balls, but eventually I will have to have a bigger cage (more money) and he will take larger rats than balls when grown(which means more money). Red Tails are pretty docile, mine is more tame than most of my ball pythons. If you know you can handle it, then red tails are a pretty good "starter" snake. But if you have any doubt on being able to handle a grown boa, have a large cage and larger food expense, I would get a ball python, and then maybe move up from there.