Here is a real world example from when I sold my MacBook in December, VAT was at 15% so the fees will be slightly different.
2006 first generation Apple MacBook (2GHz, 2GB RAM, 120Gb HDD) 7-day auction, no reserve, no buy-it-now.
Final Sale price: £432.00
Postage & Packing: £19.99
Total: £451.99
Listing Fee: £1.30 (Gallery Plus, Subtitle)
Final Value Fee: £39.97
PayPal Fee: £15.57 (on £451.99)
Total: £56.84
Total - Fees - P&P: £375.16