Don't tell someone they are wrong, especially if you don't have a definitive ID on the critter. Whenever you correct someone you should always be able to provide back-up that confirms what you are saying without_a_doubt. We often see or hear things we want to, but it isn't reality.
You could go back to the shop and say you want to take some pictures so that you can show your friends and make sure you get the right subspecies so that you can get the right care sheet. Then PM me the photos, tell me which shop it is, and then I'll snag a leachi at a great price.
Seriously, it probably is the wild caught gecko that the other guys suggested. Pet shop folks can sometimes be dumb or ignorant, but if a high value animal comes into their position, you can bet your life on it that they won't lose tabs on it or sell it for significantly less than its worth.
p.s. its been a couple weeks, did you take the critter home?