Villian had been calling and betting when he'd hit near enough any part of a flop, be it one pair, or two pair... should I have really let this go when he pushed however?

POKERSTARS GAME #3126170680: TOURNAMENT #15459656, HOLD'EM NO LIMIT - LEVEL VI (100/200) - 2005/11/22 - 07:27:44 (ET)
Table '15459656 1' Seat #7 is the button
Seat 7: MikeMcL (7055 in chips)
Seat 9: HERO (6445 in chips)
MikeMcL: posts small blind 100
HERO: posts big blind 200
*** HOLE CARDS ***
Dealt to HERO [Qh Kd]
MikeMcL: calls 100
HERO: checks
*** FLOP *** [7d 3d Kc]
HERO: bets 250
MikeMcL: raises 250 to 500
HERO: raises 750 to 1250
MikeMcL: raises 5605 to 6855 and is all-in
HERO: .....