he was only allowed to charge £1.00.sellers are not allowed to add ectra on the listing so he was breaking the rules

I hope you can all help. I won a dvd set a few days ago, was invoiced and paid the invoiced amount via paypal (item no 120592262463). This morning I recieved a demand via paypal for further payment of additional postage as he could only charge £1 in the listing. I've checked the listing and it does say to add an additional £4.50 for postage at the bottom, something I didn't see at the time of bidding (despite it being big enough - I probably didn't scroll down to the bottom) - I simply wouldn't have bid had I seen it. My mistake probably because it just didn't occur to me that someone may have additional charges on the bottom of their listing, however, while I do appreciate it will cost more than £1 to post, I was under the impression that sellers added it onto their minimum price for items. I've bought a few similar items with no issues.

He has listed similar items previously without charging additional postage. I've replied that I've paid the invoiced amount and am within ebay rules.

What's likely to happen next please?

As I say, I'm not mean, but £4.50 postage would have altered my max bid (which the item almost made by pennies anyway), and someone asking for an amount outside what ebay allows them to charge would have stopped me bidding in the first place. Item is now paid for, but I think I have an unhappy seller on my hands