eBay has a huge number of auctions for both new and second-hand items, many selling for under £10.  Some items have a 'Buy it now' option which means you can buy the item immediately at the price quoted (instead of bidding in an auction and waiting to see if you have won).  The SitesForMums team has used eBay many items and has never been disappointed but for extra peace of mind, only buy from sellers with a star next to their name because this means they have been reliable many times in the past.