Im going to push now .... but

[Shakespeare]

This is where I might not be aggressive enough, or am I doing the correct thing?

$30 sng, 4 left, 100/200 blinds, I am on the button and have decided to push with this hand, however utg has decided to limp. I have 800-1000 left, everyone covers me.

I normally now change my mind and fold, unless I have a strong hand, is this a mistake?

Lets say the limper is a tight player with reasonable raising stats, should I fold or push? The question I ask myself here is why is there a limper?

Does your decision change drastically if the player is loose?

I have ~400 $30 sngs, 39% itm, 17% roi, 4th place to 6th place = ~12% which I think is way to high? I think the types of decisions I make on near the money is costing me $$$$.

[hummusx]

I would say that in most cases you do not want to push your 800 chips over the top of someone that limped in for 200 unless:

a) You actually have decent cards

or

b) He's been limping a lot, and seems to be willing to let his hands go. Especially if he's the chip leader, I think your FE here is almost nil. You also have to consider that other players may decide to call where they wouldn't otherwise since the pot will be sweeter. 200+100+200(limper) + 800 = 1300. The BB (and limper) only need to call 600, which is over 2:1.