Equity - am I getting it right?

What sort of hands might you limp under the gun then 3bet vs a raise?

Though i am by no means an expert i spent quite a bit of time playing 2NL and 5NL and a lot of players do the whole limp/3-bet thing with AK/QQ+. These are the same players that will min bet the flop and turn with a big hand then bet big on the river. I'd fold preflop to this kind of play at the micros unless you have a strong starting hand or a decent pair and the stacks give you good odds, because they love to stack off with overpairs.