I'm going to step up and put in a vote for GBBs, if only because they're the most fun to shoot of any airsoft guns. Period.
Price difference can be kept to a minimum, assuming you weren't planning on buying some POS UHC springer (if that was the case, you can stop reading my reply now). You're paying $100-150 for a decent TM springer, and $200-250 for a good used GBB.
I dunno about you, but for me, racking the slide before every shot is 'Meh' at best. Someone proficient with a GBB can put two well aimed doubletaps on you in the time it'll take you to take one shot (if you're still alive to take it).
People do get kills with springers, but it has more to do with a player being stealthy and capable of sneaking up/ambushing a target than the springer being an formidable weapon. If nothing else, the springer forces a player to be extra careful since he'll be massively outgunned in an all out firefight against GBBs/AEGs/AEPs.
Also true that GBBs (gas guns in general) don't work well in cool/cold weather; this only matters if you plan on playing in cool/cold weather. Green gas works in cool weather. Some stock mechboxes crack in cold weather, too, and people just don't go out and play if it's too cold anyway, in which case thd gas thing is irrelevant... this all depends on you. Will YOU be out in the cold?