I recommend starting at the lowest possible bid amount knowing that you may risk selling the item for under it's "value".
If you can attract more people to your silent auction, however, then starting lower is low risk. Because people will know the value, they will fight for a bargain and end up bidding higher after being "sucked" into the competition.
On the other hand, if you start at higher starting bids, then you'll be certain to get a certain price for it, but will risk lower returns.
Here's an example I experimented with on eBay when the Pokemon cards were hot in 1999. I purchased the Starter/Zap/etc.. Decks from Wizards of the Coast and placed them on eBay. I started several decks at the price I paid for them, $9.95. The auctions often ended between $10-$15. Rarely above $20.
I took other decks and started them at 1 penny. Most of them sold for over $20 with some selling over $40 because people didn't want to lose the auction. They watched their auctions like a hawk and bid to win. The auction attracted bargain hunters at first, and then they became desperate to win that particular item. I ended up starting 5-10 decks a day at 1 penny starting bids.
I used the 1 penny starting bid for all my high ticket items too, such as computers and electronics. I rarely lost money if the item has true value.
The above only works if you have enough people coming to your auction AND the items you are selling are of value to your supporters. The Internet is a bigger market place, and people worry less about not attracting enough bidders.
If your PTO doesn't want to take the risk of starting low, then you can always set a price. The items that don't sell, you can always sell on eBay.
Good luck!
Andy D.
Disclosure: I have NO financial interest in the above activities, nor do I hold stock in any of the companies mentioned above.
[ 11-15-2005, 09:53 AM: Message edited by: Andrew Doan, MD, PhD ]