Would all of the auctions have to end at the same time, or could each auctioneer chose their own ending date and time? The auctions might raise more money if their end times were staggered. If someone had $X discretionary money to spend and if they were interested in two items, they might choose to bid only $X/2 on each auction if the end times were the same, but they might be willing to bid a lot more on the first auction and then bid their remaining money accordingly on the second auction.
Joy,
Lynn
