See here for a full list of fees.
http://pages.ebay.co.uk/help/sellerguide/selling-f
ees.html#fvf.
There
are several types of fee. You will be charged a listing fee based on the level you set your opening bids at - this ranges from 15p to �2. There is then a fee based on the final sale price, this is 5.25% of the price up to �29.99, then 3.25% of the balance of the price up to �599.99 (1.75% over �600). There are other fees, for example if you want to set a reserve price, make it a Buy It Now Auction, or increase the visibility of the auction with extra photos (you get one free), making it a featured item on the page etc.You also have to pay to get your auction to start at a specific time - otherwise it will start as soon as you finish inputting the details. If you sell something for �100 then, assuming it was an ordinary auction with no frills, it will be around �3.84 plus the listing fee of between 15p and �2.