This make a little more sense now that I think about it.
Several years ago we were looking around for a cheap fixer-upper house to buy. We found a big place by accident on an acre with irrigation, and two bedroom mother-in-law cottage, but the price wasn't listed. We called and set up an appointment to look at it.
The main house had obviously not been lived in or maintained for at least a decade or more. The roof was collapsing in so bad you could see daylight through it, there was water and weather damage everywhere, the foundation seemed ok, but there were mature trees growing right on it.
The owner was widowed Chinese immigrant, and she was asking $280K for it. The market at the time would've paid the value of the land only, but even if the house and land were in perfect condition it would've gone for $200K max. My (then) wife, who has some knowledge and experience with realestate discussed it with the realtor while I listened.
The woman was more interested in telling people that she owned a big house and what she was asking for it than she actually was in the house.
In this ficus nursery context, the sellers are getting as much prestige from the prices they're asking as they are from the money they actually get in sales. They can claim it's a $300K tree, and say that the buyer was a cheapskate for only paying $10K, or that they themselves gave it at a discount to be nice since their business is so successful. Meanwhile, the buyer can claim that he's such a great negotiator that he got a $300K tree for only $10K. High price tags that no one will pay become a socially mutual benefit.
You're either an idiot or an asshole for asking what you expect to get out of the tree and sticking to it because you didn't play the game with everyone else.