I have just had a buyer purchase 9 items but has not as yet paid as she is asking for a combined postage cost (OK with me). . However, of course ebay has added up the individual postage costs for each item, which comes to $93, instead of the $32.50 I can do it for. There does not seem to be any way for me to change the postage amount on the invoice - how do I do this?

I really don't want to ask her to pay the $93, then refund her the difference then chase up ebay asking for the excess FVFs to be refunded to me.