Exactly teo, depends on what records are in the collection. I took a box of some duplicates I had into Music Millennium and got $400 for about 2/3 of the contents. The MM buyers know what's collectable, are honest, and pay fairly.
One of my 7" 45 RPM singles (by The Nerves, a trio whose members were Peter Case---later in The Plimsouls and a solo artist, Paul Collins---later in the great Power Pop band The Beat, and Jack Lee. One of the songs on the single is the original version of Jack's song later covered by Blondie, "Hanging On The Telephone") alone fetched me a hundred bucks. Lots of 1950's Jazz LP's are worth good money, as are some small-pressing cult artist psych LP's, mis-pressings, Elvis' Sun Records 45's and 78's, soundtracks, and lots more.