I'd hope someone would be a bit lenient on price if it's a main PC player.
That being said, it depends on how the price proposal came about, say I asked someone a price on an Aminu I need, not knowing how attached to the card they are I might get a good or bad price, which is fair enough. I have some NT RPA's which might be of someones PC player, but since it's my fav set I'd have to get a pretty go offer to move them. If it's the other way and they approach you with a very high offer knowing if for PC, I think that is pretty unjust.