Personally, I think it's the responsibility of the seller to disclose shipping/handling terms; and the responsibility of the buyer to agree to those before bidding.
When I see a seller with what seems like disproportionately high s/h costs I usually choose not to bid on that auction. The aforementioned case (dovebid) was a very clear exception to that rule.
It's obviously going to be a point of contention if either the buyer or the seller isn't clear on the full terms of sale.
/ac