JHB, here are a couple of examples on the "pre-filled in silent auction bids":
1) A $20 value item-start with the first (minimum) bid of $5 or $6, then use $1-2 increments, i.e., $5, $6, $7 or $6, $8, $10....
2) A $100 value item-start with the first bid of $20, then $25, $30....
3) A $300 value item-start with $50 then $60, $70, $80 ....
I would also suggest adding a "guaranteed purchase box with say 150% of the value of the item...say a $100 item..."guaranteed purchase" amount of $150...whoever enters a bid of that amount closes out the bidding of others on this item...they get it, and no one else can bid higher...
To summarize the rationale behind "pre-filled in bid amounts...1) no mistakes on minimum bids, 2) no mistakes on the bid increments, 3) less time spent in "front of the item" to protect the item and keep others from bidding on it", 4) avoiding minimal bid increases, 5) avoiding the previous mentioned problem of bidders changing their bids on a "higher line".
One more thing...when I work an auction of this type, I also work the Silent Auction...using the P.A. to announce the current high bids on a few items every few minutes...as well as to tell Bidder # X that they are no longer the High Bidder...and when the category is about to close, I manage the closing, and if any item is highly contested at the last second...I open that item up for a "mini-live auction" between the final bidders...thus getting higher bids and not letting the "clock" prevent additional bidding. Sometimes I get 50-100% higher bids in these mini-live auctions.
Norman O'Neal
President, Auctioneers Association of Maryland