All numbers are approx because I'm bad at remembering stuff. MTT 27 players left only top 5 paid £2.3kish for 1st, I'm playing for top 3 minimum really.
Blinds are 200/400 50 ante, 5 mins till blinds raise again to 300/600
I get

in SB and I have about 6.5k at start of hand
3 or 4 limpers plus both blinds are in so about 3k in pot
Flop

I check in SB and it gets checked round to last but one player who bets just shy of 2k maybe 1700 or so, button folds.
I'm next what should my move be? If I go all in its about another 4k on top of bet.........