RE: Aftermarket Magazines
With regards to aftermarket mags: it depends on who makes them.
I have no experience with Eagle mags -- but only because I haven't seen any advertised for guns that I have that need extra mags. I'll try them when the situations arises.
Mec-Gar are aftermarket mags, and are just about the best you can get. Mec-Gar makes original equipment mags for most of the major arms manufacturers, including Beretta, S&W, CZ, H&K, SIG, EAA Witness, Kel-Tec, Taurus (for some models), and others. (In fact, Mec-Gar is now the ONLY provider for SIG... Which explains why you can't find NEW Mec-Gar mags for SIGs.)
I've never had a bad Mec-Gar mag, and have only heard of bad ones once or twice...
I've also had good luck with Chip McCormick mags for 1911s, with Pro-Mags for CZs and S&Ws, and Magnum Research mags for CZs.
Wilson's 7 round mags for 1911s are considered the best there is -- and only Colt mags have as good a reputation (for 7 and 8 -rounders). Pro-Mag hi-caps for the CZ-75b/85 Combat are generally around $15, while factory mags are $35 - $40. I've had more factory CZ mags fail than Pro-Mags...
On the other hand, I've frequently had problems with factory mags for several brands of guns...
(That said, I've seen enough of USA Mags to know I don't want anything they offer...)
Ask around: there are GOOD aftermarket mags, and they'll save you a lot of money. But there some real junkers floating around, too.