Just looking around at this eBay Guaranteed Delivery option, and after I reviewed several listings, it seems that ebay selects your fastest shipping option to meet the guarantee and displays the cost to the buyer,
I searched for a purse and ebay displayed a little over 20,000, some of those were around $12 but shipping was $36, $52, and $87 within the US.
I think I need to go back and look at my shipping options and maybe get rid of the "overnight" ones, I sure don't want to sell an item for $10 and charge $100 to ship, customers will think I am trying to pull a fast one on them even if true cost.
