I try to tell any body that will listen that the MKIII is better than the MKII, hoping to keep the prices down. I buy almost every MKII, I find locally if the price is decent. They don't last long, if I don't get them. Interesting that the prices haven't gone up much. Although I passed on a 50th anniversary gun, that was over $500, it sold in less than a week.
Really if I didn't already have so many MKII magazines, I probably wouldn't mind the MKIII's. No way I'd pay more for a used MKII, than a comparable new MKIII, at least not yet.