The problem with a high starting bid is that, unless you have the time or ability to sit through the entire GP auction to wait for an unsold item to run through again, you can't put in what I feel would be a reasonable bid. At least GL would run an unsold item through at a lower price at a later auction, so you would have a chance to enter a lower bid without sitting several hours watching the GP auction.
As an example, I'm not going to pay $300 for a rusty M105A2 with no sides or cover, but I have bought many for $125-250. Since last Jan, GP has sold 123 M105a2 trailers (21%) from $50-275 out of 594 trailers. Another 127 of the 594 trailers were sold at the starting bid of $300 (I bought one with a cover at this price because I couldn't watch the auction). That's 42% of the trailers that sold at or below the starting bid. Even GL had to drop their starting bid on these trailers from $150 down to $50 because so many were getting no bids.
Often, a low starting bid will generate more interest among potential bidders, and the resulting sale price will be much higher than with a high starting bid. I've seen this many times at live auctions where no one will offer a bid at a high starting price, but many bidders will jump in when the auctioneer drops the starting bid, and the ending bid will be much higher that his first starting. Once people start bidding on an item, many times they will get carried away and bid much higher than they had intended to ( I know I've done this!).