Here's a site that has Magpul PMags in stock and, at $60 for the Gen 3M, they will probably have them for a while. Needless to say, I removed them from my favorites list and will never buy from them again.
Magpul NEW Black PMAG 30 AR/M4 GEN M3, 5.56x45 [MAG557-BLK] - $60.00 : Gunkings.com, 10-22 and AR15 Parts and Accessories