I've gotten to the point that, unless it's a white whale or a very top-level card which is costing me lots (therefore a high shipping cost is a small fraction of the total cost), I will not even consider a bid.
I find that $3.00 for a single/insert, and $4.00 for an auto/GU is as high as I'll consider... unless it's something that has to be shipped via UPS, or some similar courier service.
Why do business with those sellers who are trying to make a profit through their S&H? If we buyers all just ignore them and don't bid, maybe those surcharges will come down. Gotta let 'em know we're just not gonna take it anymore! 
Michael.
