Agree with Frank...believe there was an auction last week for a midgrade X-Men where the shipping was more than the final price...seller can do what they want of course, but not a huge fan of auctions when the dollar amounts are low.
Also, on a more insidious note I think sellers are a fan of the self-bumping (not an attractive new word there ) nature of the auctions. With the exception of comicwiz's widget, everytime someone bids you get knocked to the top thread. Seems to be a lot of interest of late in the prime real estate for your thread...can definitely get a leg up with the natural advantage there.
Personally, I like Brian's approach to the auctions. Put the items up for sale, if there are no buyers at your price (or reasonable PM offers) then throw it up for auction to the highest bidder. Get the best of both worlds there (thumbs u