Here my two cents for what it's worth.
Great idea to have all bids end at different time. You will absolutely maximize funds raised.
But it is a double edge sword where you may also turn off those with limited funds that are expendable for such an event like this where there only way to win is being there at the right time in space.
Even though it for a GREAT CHARITY, sometimes in life we have to stop the drool from ruining what is suppose to be a fun event for all who are members here on Tradgang.
This bidding where it gets extended by 5 minutes is something I've used quite exstensively when I bid in the construction field called "Reverse Auctions".
A concept that recently is not being used very often anymore to many reasons (mostly contractors thinking with the notion when bidding that "If he can do it for $2000 then I can do it for $100 less” attitude many have gotten burnt and the Owners have to deal with a crying contractor's)
When we've bid it is set up for say a 20 minute window. When a bid is placed within the last 2 minutes, 2 more minutes get added on to the clock. So if a bid is placed with 1.5 minutes left, there is now 3.5 minutes. I've had bids go 2 hours with only 5 intials bidders starting and two of us fighting at the end. And that’s with contractors basically bidding down their profit margins.
Here with more bidders bidding up which theoretically could be endless, it will most likely go longer then what one might expect.
So be prepared for the really "wanted" auctions to spend alil time by the computer bidding.
There are a few issues to think about.
1- Do you have the program for a live auction that extends like that? Big companies pay big dollars for this. Perfect Commerce in Texas is the one I deal with when I bid for Utility companies here in the Big Apple.
2- Times left to bid will vary on each ones computer as you must wait for your browser to refresh after each time a bid is placed in the auction is extended due to multiple bids being placed at the same time.
Good luck with any way you go.
JIM