The flip side to eBay is that if you pitch the starting price too high they think you're just out to make a heap of money, whereas if they want to throw away silly-money on something that started slightly lower, then that's their business.
I wouldn't start it at more than £10, if I were you.
(also bear in mind overseas bidders - £10 = $16, whereas a starting bid of £5/$8 might look more reasonable - at the end of the day, market forces will dictate if it sells or not)