Just want to add, that in low buyin MTTs its also going to be a very common occurence, that one or more players have limped into the pot, when the action gets to you. If the original limper has limped UTG with a 13BB stack and is playing 13/11, then its probably a trap, and I will typically fold or knock my option.
However the more typical scenario is, that a fish limp into the pot with some marginal holding, another fish limp behind, and then a reg limp behind on BTN. And in these kind of situations I feel, I have literally printed money by jamming it in with even fairly large stacks and either picking it up a ton or getting it heads up against someone, who decide to play the table sheriff with his 44 or his A6 offsuit 🙂