Ack! I've had things happen but not usually to this extent.
I'd think the machine would be worth fixing, it may take some time and more money than you'd expect, but this is hopefully something that someone who know how to get where they are going can fix it. I gave up on repairing my modern/computerized Bernina 820 (not a happy story) due to the increasing price/scarcity of the piece that kept breaking -- It would have been my 4th? in 7 or so years. The parts alone this last time would have been about $600 without labor and I decided to use that as my shopping budget for a new machine. I was ok with the $200-400 I paid each time before but I had enough into that particular machine which, while great when it ran, was never my favorite machine.