[Arran]

I think that most antiques dealer are purposely putting high prices.

1- they do put time to make what they sell presentable.
2- if they sell less, at higher price, they make about the same money as more for less.
3- if all antiques store sell with high-price, the average antique price will go up.

But you missed the point, they hardly sell anything. How can you keep the lights on and pay store rent if you don't move any merchandise? The average antique price is set by how much a buyer will pay, not some arbitrary price set by a dealer. As the old axiom goes, a bird in the hand is worth two in the bush, it's better to actually make a sale a the first reasonable offer then to try seeking those "two birds in a bush" prices because it costs money just to keep it there. Many just don't understand this, merchandise looses it's value the longer it stays in a store, if they paid $50 for something, price it at $100, if it stays there for six months the profit on that item has already been eaten by the overhead, if it stays there for a year it ends up costing them more then what they paid.
I can give you an example, there is a store near me that has a Philco 20, a plain box Philco 20 that does not work, has a dumb sign on it saying that it "Needs a tube", they want $330 for it. It needs a pair of 71As which some dummy replaced with a pair of 45s, I've gone in there and explained this to them, my uncle has done the same and has offered to sell them the right tubes but to no avail, and it still has that same dumb sign on it. That was a year ago and the Philco is still sitting there along with the same Bakelite radios they had 10 years ago. Plain and simple they don't do anything with their wares to make them more presentable, they just don't care.
Second hand stores at least, of which most antique stores are pretty much a glorrified version, depend on foot traffic coming into the store to make a sale. There are people that browse the stores once a week or once every two weeks, if they see the same stuff sitting on the shelf week after week, month after month, and nothing new coming in they stop going to that store. Around my area these places come and go almost as frequently as restaurants because of this, they just simply have no business plan. Many of the ones that stay open but still don't sell anything have to be either tax write offs or money laundering operations, there is no other way that they could pay the rent and keep open otherwise.
Regards
Arran