That is a nice clean original for sure but the seller is dreaming on the price. I had the exact same machine--not in as clean of shape and mine had some damage to the metal where the side lock had been removed--and recently sold it on CL for $300. It was listed for quite a while before I got a buyer but it did eventually sell. While that machine does have the gum/mint wheel which adds value, it is the later mid-50's styling. I like the older art-deco Stoners. BTW--nice popcorn warmer in the mirror.
If that one is as clean as it looks and in complete (with coin mech) working condition (the seller does not make that clear in his ad), it would be worth $300 to $500 because you would have a machine that looks good without any work and you could use it right away. At that price I would not expect to flip it and make any money though.
My two cents anyway!
Tim