[howzit]

HOWMANY, 3 bet means see y'all at the river.

hands that will not fold to the 3 bet:
A2+pair
nut flush draw with BS low draw
top two/ middle and top set/3 pair
2-6 straight wrap.

hands that might fold:
A2xx
counterfeit protected low, rainbow (a nit would fold)
bottom two/ topbottom two pair/ naked bottom set

hands that will fold:
overpair
A3xx

so looking at those hand ranges: hands that are drawing liver than yours or have you crushed will stick around. is it worth trying to knockout button's naked A2draw to get position? probably not since he's yet to act and you have no idea if he has A2xx to begin with and if he did have A2xx, it's impossible to know if it's a oneway draw.

i'd toss it in the muck BUT now that we're here, calling is a better play since the button might read your cold call as a naked A2. so he might dump a naked A4xx. but then you're still dealing with two guys who probably have you beat and 3 betting them will insure a showdown at the river.