Thing I carnt understand is if you dont agree with the postage costs then you dont bid??

I think the retard has seen that he has paid to much and is trying to get a few quid back.

Thats the next line of attack;

Dear time waster, I have recalculated my postage costs and loss of interest on the money you withheld from the item you won on Ebay and infact you know owe me a further £1.50. Please pay ASAP.

Thank you please.