That's a 1200, it's a 201 in a commercial table with a knee lift for the presser foot. They're called the dressmakers or tailors version of the 201. I can't remember when the 1200 began, but I do know that up until the 1950s the 1200 wasn't listed as such in Singers records, it was listed as a 201. Only the last few years of production it was listed in the records properly.
While not a great deal, $400 isn't out of line if the machine and table are complete and operational. If it were me looking at it, I'd tell her you'll pay that much if she pays to get it serviced. The 1200s aren't incredibly rare, but they're not common either.
Cari