For that price, you can probably MAKE them work.
I picked up a bunch of Magnum Research mags (for the Baby Eagle, but supposedly functional for the CZ line) a couple of years ago.
Strange little beasts, with a coil spring attached to the top of the mag, with a follower that rode down, uncoiling the spring as it went.
Had the bottom fall off one during match once, and it kept on working. (I was surprised with the SO handed me the mag bottom... Didn't need it to function.)
Someone has since said they were made by Ramline.
Now, Ramline may produce to different standards of quality when making their own than with making mags as an OEM provider, but those mags have been absolutely great. (And that's the price I paid, from CDNN.)
Might be worth a gamble...
