Well....................I have bought and sold a goodly number of these in the past three years or so, both at Eastern Ontario gun shows and here on Gun Nutz. I would buy large quantities of new mags if I could get them at fifty bucks. I would buy as many used mags as I could lay my hands on for thirty bucks.
My own experience has been that both the older style and the newer style mags sell for roughly the same price, although the older ones typically get about a five dollar premium.
If I was BUYING the mag described, (clean, no rust, G to VG condition) I would pay probably forty bucks. If I was SELLING the mag at a gun show I would be listing it at $65 and take $60 for it.
HTH.
Doug