I do not buy bulk cards not in the 70's as they are generally worthless. A few select cards i would be interested in from then. Cards from the 70's, preferably 75 and earlier i will buy in bulk good and bad depending on condition, but most cards from then also don't carry to much value. True value (5-10 per card if not much more) Is generally limited to the 60's and earlier.
My offers come from the general going rate on eBay, but obviously not that full amount. But thats where i begin evaluating, because book or beckett value is semi meaningless.
Thanks for all interest!