AEQ, especially the % kind, is most useful if you can get 2 of them to build upon each other. If you think you can pull that off I'd buy the 2% and wait on another later. The 3% difference is much less noticeable between 30% and 33% than it is between 12% and 15%. If you don't want to shop more (or already have another piece you like) and just want to move on with your life I'd grab the 5%.
I also have a massive AEQ dilemma (why I came here in the first place):
I have 3 pieces, choose 2:
+5% BB/+2% int
+1 vision/+1 Blitz
+1 Blitz
Basically do I want to stack the blitz pieces and forego the beautiful BB piece, or should I keep it and sell off one of the Blitzes? This is an agility/speed DE who will have 8 Blitz at level 40. Basically it's 8 blitz vs 4 blitz/15% BB for a DE with about 100 agi/85 spd. (note, this is a lucky player, I've only shopped 5 times in his career, and might be able to get all 3 of these pieces going late in his career due to a plethora of BT's. For the record I'm convinced that THE time to shop is levels 36-40)