how does the mags works and where to get the best price on one.....
The mechanism for the AICS mags is similar to the M14 system.There is a "catch" on the rear of the mag that interacts with a lever in front of the trigger guard.
AICS mags only work with the AICS chassis, and they are quite pricey these days. The 10 round mags are around $150.00 each!!!!

When I bought my Chassis in late 2000, the 10 round mags were $109.00 each........
The price on this stock/chassis seems expensive, but remember that you also get a reliable detachable mag system with the chassis.A McMillan stock will run you around $1000.00, and then you need to have it bedded, and then the added cost of a detachable Mag system (which will require the stock being inletted for the particular system you choose) if you want to go that route.
The AICS is advertised as not needing bedding, but you should do a light skim bed job on it for a perfect fit.
I have the 1.0 AICS and love it.However if you have larger hand it may not be to your liking.Try to find someone in your area that has one and will let you at least hold it to see if it's comfortable for you.
SKBY.