I was able to go get the machine during lunch time. The total is $509 - $129 for standard tuneup, $170 for labor on replacing the feed dog step motor and $210 for the part.
I asked for a copy of the estimate notes and was told I could not have a copy. That people would then take it somewhere else to get it done cheaper. Okay, I understand that if I had not just paid $25 for diagnostic. Oh well.
In a bit I will see if the embroidery unit will work at this point.