There's a book called Record Collectors Price Guide which gives values on vinyl releases, but it's a bit expensive - about twenty quid I think. There's also a website called Discogs which people use to sell their vinyl, so you can get a good idea of what a record's worth (sorry, can't post link, as I'm on my iPhone at the mo'). As Yes albums sold in large quantities, wouldn't have thought it was worth much, unless it's a rare Taiwanese picture disc or something similar!
