There's some reports floating about that someone on the black market has a Peruvian Vipertooth egg. If you're the kind of person that trades in these kind of things HAGRID, gentle reminder that:
The Vipertooth likes the taste of human flesh. If it gets a nibble, it won't stop. It's not like a puppy that's just teething, ok?
Dragon eggs need a lot of heat in order to hatch, but too much may kill the baby dragon inside. Which is generally why dragonologists prefer to allow eggs to hatch inside a dragon's nest rather than incubate them artificially. We've seen this happen when rescued eggs have been delivered to the sanctuary. It's really sad.
Dragon eggs are considered a Class A Non-Tradeable Material.
There are a lot of fake eggs on the market, so tbh it's really not even worth handing your gold over for it since it's probably not even real.