I normally stay clear of AIBU but really can't tell if I'm in the wrong here. So here goes.
I've just sold something (an item of clothing- not heavy) on eBay. As soon as it sold I received a message from the buyer saying that the postage is too much and I can post it in a large envelope and amend the invoice.
As far as I'm concerned it's not that steep £3.95 and this was on the original listing. So it's not like I haven't been transparent.
So AIBU to tell her to forget about it then if she's unwilling to pay the stated price and just relist it.
I don't sell much on eBay for fear that it's more trouble than it's worth!