I got mine for $50 refoamed (not the masonite type) but with much worse cabinets and grills than the picture lloks like. You can refoam them cheap or spend $20 or so to get the right foam.
So, I think $30-40 could be a more acceptable price. I got another mismatched pair for $20 which needed refoaming (with the masonite). If they are in really nice condition and you like their sound (heard before) then even the $50 is acceptable.