A question about smaller pairs

[Tropex]

I'm just recently moving up to the first midstakes (\o/) And I was kinda wonderin'... It has been pretty easy to make constant profit up to NL100, so here's my question about the not so high pairs. Ranging from, well 22 to 99 or TT...

So let's say you're in BB and CO or Button makes it 4 BB. Will you call the extra 3 BB every day, every night, even if you assume you're behind against a bigger pair in hopes to hit a set. You get huge payments for sets in the lower limits, but I'm not 100% sure whether it's worth it. And what if you're on button (ie. in position, are you willing to call the 4 BB)?

Obviously the implied odds go down as the stakes go up as people are capable of making better laydowns.