I've paid 75 to 100. Took my Pfaff to place that charged 75 and had to bring it back twice and the problem came back again almost immediately. Went there also because it's closer to home and shop sells fabrics. Should have taken it to shop where I bought it but didn't because it was too far away and no fabric there. So what did I save by going to the cheaper place twice? Nothing. Anyway, I've upgraded my Pfaff and it has a 5 year warranty which includes annual checkups. I do a lot of sewing, clean the lint out whenever I change the bobbin, etc. I've found that an annual maintenance keeps my machines running smoothly.
May in Jersey