1) work in reverse, with a team offering to the Bills a trade down for them, and a trade up for the Bills, and using the rest of the offerer's clock time to run a poll, and if the poll rejects the offer, give the offerer another hour or so, and if the trade up poll works, you need to run a poll on who we are selecting with that trade up, the same as for a trade down.
2) create a specific trade up window, where everyone who is interested in trading down, can post there offers to you, and you create a poll among all the trade up offers to see if the Bills fans want any. You could have have a scheduled time say 7 to 8 Est time to run the trade offers poll each day.