Not wanting to start a GBB vrs AEP discussion/derailment, and i know its not a GBB pistol, but i highly recommend a CYMA G18c AEP :-
its cheap (£60 - £70)
mags are cheap (£30 for 3 100rd mags on ebay)
no gas usage (change it to lipo's (£25 for the adapter plate, then £3.50 each!!! from hobby king) and i get 8 - 9 mags out of a 300mAh lipo

thats 800 to 900 bb's! if mags are full)
no worry of leaky mags or temperatures causing mags to vent :blink:
easier to maintain (as easy as a AEG)
Very very nice range for its size (i use 0.25 blaster bb's)
It dose have a few down points :-
no blow back therefore not much kick at all
and only around 180 - 200 fps
out of my 6 100rd mags one has failed
at my last secondaries day, it worked flawlessly all day, and i had to change battery twice that's how much i used it, and that's not in full auto either! i have since got a serpa, and it now on my assault vest all the time.
rather than add another post, i'll add to this. There is a common myth that AEP's have a slower trigger response .... i can assure you, mine on its lipo's is as fast as my Hi cappa, and faster then any of my AEG's (but we are talking milli-seconds here). unless you have your trigger permanently depressed to the point of release with a GBB, i wouldn't say they were any faster.
GBB's are alot of fun, look really cool .. but do require alot of maintainence