"It's entirely possible the music shop owner didn't fully realize the full value of the violin as well"
Since only one dollar amount is quoted in the OP it is also entirely possible that the shop owner was tryin to low ball and steal a gun.
If the store owner makes an offer and the gun owner accepts the offer there is no "stealing" involved.
We could haggle over terminology until the cows come home and get nowhere. What I mean is, and I know you have seen it, a shop owner offering an obviously uninformed customer a low ball price and touting how good an offer they are making. Call it taking advantage call it what you will and be happy. I'll just call it what I think it is.
