Yeah, those guys are pretty pricey. But they are incredible, and are very rare in collections, and quite beautiful. It doesn't so much depend on how much they are worth, but how much they are worth to YOU. For knob tails there is not all that much competition so it is basically a sellers market out there. Since there really aren't too many people who sell those, it's basically you pay what the owner thinks is reasonable or what he thinks they're worth. There are market prices for these geckos, but they differ drastically, depending on whether they are adults, juveniles, or males/females. Knob tails are awesome and their price reflects this for sure..