Joe,
There is a pretty big variation in valuation on old vinyl; condition, artist,number of copies etc. You need to locate some used record stores for appraisal. Generally the people working in these stores are very helpful and knowledgeable. Be sure to visit more than one store and hopefully you will happen onto that employee or owner who's life revolves around the music biz and will be eager to help you with valuations.
Good Luck, Brian
