BP's have been everywhere for a very long time now, which isn't surprising as they breed at a relatively young age, they are easy to breed, and you can keep quite a few in a small space. Boas take longer to mature and get bigger so you don't see as many. Savu pythons are rarely, if ever, seen because females don't mature until 5-6 years old and they have small clutches, so no one intending to breed for quick $ wanted to wait that long.