I'm gonna play devils advocate here....but. Just be aware that the 550 was much like the older combines (which were good little machines!), the 750s are quite different. And every 750 I ever saw was fix or repair DAILY. I have 2 neighbors who are brothers. Grew up running Masseys--were dis hard Massey fans. One finally bought on old beat up JD 6600, the other kept (2) 750's. Guess who got more combined faster? The one with the 750s finally got so frustrated he went and bought a JD 9500. Know a couple other people with similar experiences. Around me you literally can't give away a MF 750 combine: local guy had a low hours grey top machine. It went for scrap. A 550 still brings fair money. Just our experience...your area might be different.