OK, what's the protocol?

I generally quote shipping and handling as a charge on top of the price of the item. I normally include enough extra $ (usually $3-5 depending on weight and packaging complexity) to make sure I don't end up eating FEDEX charges; but nowhere close to a fair cost for my labor, gas, and packaging.

If the deal was negotiated as covering only exact shipper charges, then I would refund that, but only in that case which I would avoid because it's just not worth the effort IMO.

Please, I don't really have time to split hairs on shipping costs.

"Your underestimation, and eating of shipping costs in the past, does not mean diddly to your buyer who is being asked to pay more than he/she
should."

No, but, it will influence my personal shipping policy formulations. If I'm willing to refund, I should be willing to ask FOR a refund. 'Not sure I'm ready to do that. Also, Im only asking them to pay what we both agreed to.

I think if it is a material miscalculation it should be refunded. Otherwise, I think it all washes out.

I think we're essentially on the same page.

It's easier in the long run to calculate the shipping costs up front and add $5 or $10 for materials. It's not that diffcult to find the manufacturer's shipping weight and calculate cost.

If one ballparks these figures, then one lives by the estimation and moves on.

I think it greatly depends on the overage. For instance you quote 89.00 and the shipping is 20.00. If you ship ups or fedex then the client will not ever know so your final shipping price would be up to you, then your will make a determination of how you treat your customers.

But If you spent 3 hours packing the article and 20.00 for packing material and 1 hour driving to send the package away then make sure you dont cheat yourself. You know whats fair just let that be your guide.

Many items on ebay "feature" outlandish shipping fees. Trading here implies a kinder, more ethical group of enthusiasts who are in it for the love of the game, not the pursuit of the almighty dollar. There are all kinds from all walks of life. The fact that you asked at all is a good thing. Remenber that in the scheme of things, shipping costs are but a fraction of the value of the goods and therefore should not bear too much on the deal, as long it is reasonable and fair to all. So I wouldn't fret too much, unless the buyer was taking issue. FWIW, I have acces to boxes and shipping materials here at work and don't charge for that, but it does take time to properly package an item, do the do on the shipper's website, and shuffle off to FedEx. Taking the time to do these things myself gives peace of mind, and assurance to the buyer.