Good price on those steel 30 rounders... 
but pmags have always worked for me, so I'll probably just stick with em. 
I ordered "a few" of the DSG arms pmags, I think I'm all set 
I did pick up one of the nordic expansion mags to turn a pmag into a 48 round mag. At $26/ea + the pmag, I couldn't really justify more than one of em... maybe I'll regret that if I start 3-gunning next year, but for now, one's enough. 
BEST use I could think of for a drum would be a very fun shooting run with a bump fire stock. But I guess if you can afford to dump 90 rounds downrange at that speed, you can also afford the drum 
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Cheaper than dirt has come mags back in stock. No price inflation, none at all. 
ONLY $99.97 for a used 30 rnd USGI mag. 
 
http://www.cheaperthandirt.com/ItemL...spx?catid=6652
http://www.cheaperthandirt.com/product/MAG-068