http://www.amazon.co.uk/exec/obidos/ASIN/0330441256 - RRP £8 Amazon price £6. Second hand 1p.
There are quite a lot of books like the one above on Amazon for £0.01 and £2.75 postage. Just takes a bit of searching.
This exact book still has numerous more for £0.01 so go get them.
Post any more links here to almost free amazon books if you like.