MAngband

Speed rings need to have their value jacked up...it doesn't matter if I'm selling a +3 or a +9, the shop offers me 300k for it, even though each + about doubles the overall usefulness of the speed ring.

Is that/can that be taken into account?

Maybe you're hitting the cap on what the shop will offer you for your race and charisma?

Probably the shop owner's purse is too small to give you more than that. That's what the number in parentheses means.. if they only have 300k, they will only give you that much.