Can I charge more for postage than ebay allows?

[Mirage]

I've got a heavy jacket on ebay and specified collection only as the postage is about £7 but the max ebay will let me charge is £4.25.Someone has bid on it and then realised it is collection only,so I said that if she wanted to retract the bid,it isn't a problem.However she says she really wants the jacket and can she pay the extra postage.My questions are,is this possible,and if it is,how do I do it?
Thanks very much.

You can't amend once someone had bid. The lovely lady in our post office told me to use the courier service option. Price on request. You can then add the price to the invoice at the time of purchase.

change your option to courier: bulk and heavy items then put the charges in the item description, i think you have to remember to alter you invoice to include the postage and packing when you send them an invoice, (i have just complained to ebay because they only allowed me to charge £3.25 for a book but the actual cost was £5.30 so i lost out). they told me to do it this way and i have just listed an item like this although i did raise with ebay that it was misleading because i was actually going to be sending it by royal mail and they didnt seem that bothered!!!

Thankyou,I'd never have thought of that !

just remember courier charge different amounts for more remote parts of UK so make sure you say that, you can send a heavy book for £4 to london it would cost £15 by courier to shetland when royal mail would only be £5,30