While I agree that several of the Candoia group (Solomon Island ground & tree boas, Santa Isabel ground boas & Viper boas) are a good choice in regards to size, they aren't the best choice for the novice keeper. For the under $100 price range, you would be talking neonates or small juveniles that may or may not be feeding on rodents...regardless of what a seller claims. Larger and older established animals are typically going to cost more than $100 on average...it isn't uncommon to see adults run $200 and up. They can be difficult feeders and young ones are delicate, especially those new born or just a few months old, and can be stressed rather easily. Also their feeding regimen is not that of the average boa or python. They have very slow growth rates (my yearling Santa Isabel still hasn't reached a foot in length yet) and overfeeding juveniles can cause death more readily than other species. Whle they don't require the warmer temperature ranges of most boas and pythons, they do need fairly exacting temperatures...too cool will result in respiratory infections and too warm can very easily cause death in juveniles. They also need proper humidity ranges with good ventilation for good health, which is not always easy to provide in a tank.
I would be the first to recommend these little beauties to someone with experience keeping boas and pythons, that already has a good grasp on husbandry, but not someone just starting out who's only kept one or two snakes before. That isn't to say the new keeper can't care for them properly, but that they can be a challenge that would turn most novice keepers away. For that matter, I know a number of experienced keepers that have become exaperated with this species and given them up. Even after keeping boas & pythons for 13 years, and Candoia for 2 years, I still find they can be frustrating captives (I own five - 2.2 Solomon Island ground boas and 0.1 Santa Isabel ground boa). Two of the five are particularly finicky feeders and even though they are feeding on rodents it is by no means a regular occurence. Up until a recent fire at my Mom's house, she bred field mice for me as feeders for one of the Solomon Island ground boas. Since the feeder colony was lost due to the fire, I am hoping I can now switch him to lab mice but he has adamantly refused anything but captive bred field mice in the past, so my concern is piqued.
As for some of the other species Hoppy mentioned, I soundly second the rosy boas, rubber boas, and sand boas, as well as the children's and spotted pythons. I'm not familiar with the white lip pythons, however. You would have to research the carpet pythons, but the jungle carpets and Irian Jaya carpets would stay in your size range, while the coastals will get much larger than your prefered limit. The rainbow boas are also an excellent option, but require higher humidity ranges than you can easily provide in a tank IMO. The exception being the Colombian rainbow boa, which I find to be much more tolerant of husbandry errors and variables than its Brazilian cousin. I have kept my Colombian rainbow in a tank for several months now and he's doing great so long as I provide the occassional misting. I also think the Amazaon tree boas would work well, though they typically run more than the $100 range and, as Hoppy said, have a tendency for biting.
Good luck whatever you choose.
Raven
