That's my experience too. The Charity Shops are usually well and truly cleaned out by the 'crate digger' brigade (they even collect the 'TOTP' albums ). Some of the bigger Oxfam shops, especially the ones in the wealthy areas, filter out their collectable vinyl (e.g. Rendell/Carr) and have lists of the rare stuff that you can peruse. They use book value though so there are absolutely no bargains to be had. Having said that, it's a good way of donating to charity.