I just checked ebay, it seems to be all over the place, from 300 - 700. I got this in the 80's, so don't really remember how much it was at the time.
$300 is pretty normal. The $700 ones don't sell. They just sit. If you scroll down the left side, you'll see a box to check for recently sold listings. That's where you can see prices that are actually moving for whatever you searched for. Some guy made a great steal with a 50mm f/1.2 attached to a body for $40 last month: MINOLTA X 370 SLR MD 50MM 1 1 2 LENS | eBay
