i also checked this,
you are ok and safe, if you big 15 quid and it finished at 15 quid and you are the winner, you will pay NO MORE than 15 quid and whaever the P&P is stated,
IF they have not put a reserve price, or did the start price wrong, THEY have messed up and are bound by ebay sellers contract to sell you the item at the end price.
if they dont, they you can mark a claim with ebay that you have not been offered your good, you will get your money back ( if already paid ) and they will get a strike.
so dont fret.