My Grandfather gave me a box of old records (60 to 80 records) that he used to use back in the 50/60's to test stereo/record players that he used to sell. There are a lot of Command Stereo test records, which are incredible sounding, Those are the best sounding records u can find.. Also some RCA Victor hi-fi records.. Anyone know where I could find out the value of these? These are in mint condition and I was just curious of how much they are worth.