There's a lovely little secondhand bookshop in Dover that was very useful recently. On my journey through the Discwold from the beginning I discovered that my collection was missing Small Gods (Shock, Horror!)
I knew I'd read it and couldn't believe I didn't own it. My collection is by no means classic, hardback after 'Hogfather, thanks to Him each year, the rest mainly 'pre-owned' paperback. This little shop seems to have the whole series in stock, including a few hardbacks. What I don't understand is why anyone, having read Pterry would ever want to part with one of his works.