This is an undeveloped domain that I don't know if I'll use the future, so I am thinking about selling it. However, I really have no idea where to start on price.
Anyone have advice on how I should proceed with this?
it's all negotiation.
stay strong don't show your hand, just ask for an offer,
and remember a deal need not be done at the first hurdle,
eg. don't take the first offer at face value.
all the time they are offering they are interested and in the game.