This is related to valuations, but not jewellery. And it's an ark memory. When I was a child my mother (she still has it) had a Mexican Silver $ from the 1800s (she knew someone who used to give her odds and sods). She was a little down on her luck and wondered about selling it. The shop, or whatever it was pounced on her and gave her a stupid price. Stupid enough for her to say thanks no thanks. At some later date, she got it valued at a significant increase. Sooooo, if someone offers you a price too quickly, that probably means it's worth a lot more.
And as I'm here, not a joke, and for the layman, what is the difference between a valuation and an appraisal?