Dont forget prices may also change in 3 years, you can either end up spend more or less.
Im not going to comment on AEGs today, but I'll throw some comments on there on the other stuff.
However I would recommend you get your batterys from
http://www.cheapbatterypacks.com/?sid=1148815
I would also recommend a good inital investment into a quality charger.
Those silly wall chargers are not the best. If I can make a suggestion
http://www.airsoftparts.ca/store2/in...oducts_id=1030
Its a great quality charger.
Your idea for 200 mags is good, Id probly mix it up a little and get some lower ones too. Some fields have ammo carrying restrictions, and well highcaps are all fine and dandy if you dont like reloading but I dont like how they rattle and the constant winding that is needed. However thats you preference and to each their own.
The tactical vest you have choosen is not worth 90 dollars, its a simple cross draw vest that can be picked up on ebay for sometimes as low as 40 dollars.
http://cgi.ebay.com/BLACK-POLICE-TAC...QQcmdZViewItem
Im hoping you were just using buyairsoft for the sake of links, because they have been known to unreliable, not saying they are, but if you research in this websites review section you will see that a fair handful of people have had difficulties with them. Who knows in 3 years they may have shaped up or gone out of business. In 3 years there may be other additional retailers you can pick and choose from. However in time your choices may change as well.
Best of luck.