I don't think about it relative to BB raise at all really...

Here's what I consider:

(a) Stack Sizes - what are the effective stack sizes if I call? We will hit our set about 1/8. Most people look for the effective stacks to be at least 10x the bet. I look for a little more, because you usually will -not- get the other person all the way in.

(b) Player type - you want to be in against a player that is pretty aggressive, and unable to let go of his overpairs, TPTK type hands

Another note... I find that, the bigger the preflop raise, the more likely you are to get the all-in payout. The big raises mean QQ-AA, and when the flop comes 5s6s8c, they love to protect their hand against draws.