Unless you plan to buy used, there isn't any, really that are official BSA knives that are decent. The whole line of official BSA knives is made in China and of poor quality. The Remington BSA knives (replica of the old one from the '20s and '30s), which are made by Bear and Son are OK, and rather affordable (like $35), but they're small, and Bear's quality is irregular. They do have bone handles, though. Case makes a line of knives (all non-official) that are BSA licensed, mostly with your requirement of bone handles, and there is a Scout knife in that line (but it's almost $100). Non official, you've got several. The aforementioned Rough Rider is under $20.
I don't know about buying used, but there plenty both BSA and non in the Scout/Camper/Utility pattern that are excellent. I have a bone handled "Made in USA" marked Utility (made in Camillus) with beautiful Rogers bone that cost me less than $10. May of the BSA knives cost $20, and are excellent, all US made (Ulster, Imperial, Camillus, just to name a few).