So I just used the search feature and they typically sell used on this board for $290-$375 used. For that much money I would wait for an LD-340 intake all day long.
I'm seeing typical comparable condition LD340 at $100 more than RPM's. I believe there's more opportunity to get a RPM for a greater difference with patience. And the LD340's for sale are generally in worse shape than the RPM (30-40 years newer)
Also having the part number on the LD340 seem to increase the price.
At swap meets around here the RPM's seem half the cost of an LD340