Ah, thanks for the advice!
I don't know anything about the costs of them either, the parent pair/trio (I can't remember how many) ones were a gift, likely not expensive, but really beautiful fish. I think the long tails add some value, but I'd have to do some research on colouration and values on shubunkins I guess! I'd only planned to give them to the LFS just so the pond doesn't get overcrowded, but this has made me decide to look into what they might be worth before just giving them over, in case they're worth a few quid! I'm sure they won't be worth $100 or anything, but if say, each was worth $50, I'd expect some kind of payment or store credit for them I think.