The possibility of bad feedback is still a deterrent for many sellers who might otherwise considering doing what this one did with the shipping costs.
Also, the seller will get what's called a defect behind-the-scenes for cancelling an order.
According to the standards set out for sellers by ebay, the two main contributing factors for sending buyers away mad is (a) cancelled orders and (b) orders that arrive later than promised. These are the biggest sins a seller can do. To many and selling privileges will be restricted. Most sellers, when realizing they made a big mistake with shipping costs, will eat it and ship anyway.
I mean, seriously, I found ebay had made an error with dimensional limits for a large international package that prevented me from mailing the order with the postage service the buyer bought, so that it had to go via Xpresspost only which cost ME an extra $98 in postage. And I paid it and sent it. I must stress this was a mistake made by the Calculated Shipping Tool, not me, a verified mistake. And it cost me $98 in my own money to send the order to the buyer and I did not even consider cancelling it.
It's not the buyer's fault that the ShippingTool was incorrect. Neither is it the buyer's fault that the seller miscalculated the postage cost.
A purchase is a purchase. If you've paid for it, you have every reason to expect it will be shipped to you. Period.
