Welcome to the sport. Have fun!
There are NO AEG/GBB/weapon sales at the TAC08 convention. There's a pretty good sized gear swap, lots of parts/accessories/upgrades on hand and other neat stuff.
Last year there was one AEG session and one GBB session (I think...I wasn't there for the whole thing). There was also a combat knife skills workshop and product demos.
There's opportunity to try/test different AEGs/GBBs.
NO weapon sales though anywhere close to the location (TTAC3).