I would also have cancelled, as I think it would be illegal to tack on charges after the "contract" has already been completed. I buy from various sellers on eBay and what sometimes seems to be a reasonable price for a piece of fabric is totally blown out of the water by an outrageous shipping charge. We all know what an envelope costs, what it costs us to drive to the post office, and what the postage would be. If what a vendor is charging me is more than that estimate, I just don't order. You did good!