I have the 7550 and two 7570. They are identical except the 7570 has embroidery capabilities. I bought my first 7570 about 20 years ago and love it so much I bought another. Then I bought the 7550. I get them serviced about once a year and have never had any problems with any of them. I have heard of the motherboard problems but have never had any such problems myself. I LOVE my Pfaff and highly recommend it. I think $500 is the top I would pay for a 7550. Hope that helps.