If it was me, I would offer certain cards at a period of time at
closed bids. The highest bid is all you would have to consider to see if you want to sell. Not having the open platform of bidding would eliminate any hostilities between the collectors. I wouldn't do too many at a time because most collectors have a set amount they have to spend a month on their hobby. Plus I just got my property tax bill at 6 grand
just my opinion!