Impressive nolagurl, you seem to be well informed. The tuatara can also live to be over 100 years old. If there reproduction cycle wasn’t so slow, I am certain they would highly demanded herps. To the original question, rarity is the key to holding value. The afore mentioned leucistic Nile may fetch 125k now, but once reproduced that price will greatly decline. Example, albino burms. Once very expensive, now I can get them for $75. In terms of true holding value, I would guess the Komodo Dragon would be the most expensive lizard. On snakes, that would be hard to guess. Far as North American species, I would probably say the Eastern Indigo.
www.SCReptiles.com 2.2 Crotalus adamanteus. 2.2 Crotalus h. atricaudatus. 2.2 Crotalus h. horridus. 1.1 Agkistrodon p. piscivorus. 1.1 Agkistrodon c. contortrix. 1.1 Agkistrodon c. mokasen. 1.1 Agkistrodon c. laticinctus. 1.1 Agkistrodon c. pictigaster. Agkistrodon c. phaeogaster. 1.2 Sistrurus miliarius barbouri. 1.1 Micrurus fulvius. 0.0.1 Micrurus fulvius tenere