Korean mags that I've used were garbage. I know guys swear by them but I used the 4th gen ones and the bump outs and feed lips were not in spec on them. I never recommend them because these issues caused them to not lock in my clones and the bottom of the bolt dragged on the feed lips because the width of the opening between the feed lips was too narrow. I am not trying to talk trash or anything these are just my observations with these mags. I wish they worked as they are cheap!
I have several used German mags I was able to find for around $50 each as well as new ones I was able to find for $60 new when you buy in quantity. This is of course the best option but also the most costly.
I have a few dozen of the POF mags from RTG before he ran out and they run as well as the German mags. The main difference is the finish but other than being blued fit and finish is excellent.,
What I a waiting for is Zenith to get their mags in country, I emailed them several months ago and supposedly they are bringing plastic and metal mags for the MP5, HK33 and G3 into the US. I have read that the Turkish MP5 mags are as nice as, if not nicer than the POF ones. I wonder what the street price on the MKE steel mags will be?
If I were in the market for mags right now I would go for used German mags, YMMV.