Should I have just folded this preflop?

who calls the all-in? He was quite losse.

PokerStars Game #6166489224: Tournament #31261726, $12+$1 Hold'em No Limit -
Level III (25/50) - 2006/09/04 - 11:48:15 (ET)
Table '31261726 1' 6-max Seat #5 is the button
Seat 1: RandomHero83 (2385 in chips)
Seat 2: Austin520 (1560 in chips)
Seat 3: OReilly7 (1175 in chips)
Seat 4: vstathop (665 in chips)
Seat 5: chaide71 (1690 in chips)
Seat 6: Iron6000 (1525 in chips)
Iron6000: posts small blind 25
RandomHero83: posts big blind 50
*** HOLE CARDS ***
Dealt to RandomHero83 [Ah 4h]
Austin520: folds
OReilly7: folds
vstathop: raises 50 to 100
chaide71: folds
Iron6000: calls 75
RandomHero83: calls 50
*** FLOP *** [4d 5s 4s]
Iron6000: bets 50
RandomHero83: raises 100 to 150
vstathop: calls 150
Iron6000: calls 100
*** TURN *** [4d 5s 4s] [2h]
Iron6000: bets 50
RandomHero83: raises 350 to 400
vstathop: folds
Iron6000: raises 875 to 1275 and is all-in.