I agree with Charlee and others, these old machines rarely have a fatal failure. I hope your repair person gets her back running. For a secondary machine, I would also get an inexpensive vintage machine. You can work on them yourself, don't have to worry about much happening to them when they sit neglected and unused. But you may get to like it so much, that you enjoy sewing on your second machine just as much. Watch Craig's list, free cycle or garage sales and pick one up for $20 or less. If you want more fancy stitches and zig zag, look for a mid century Singer 400, 500 series machine with cams. Will probably cost you a bit more but worth it if you want that capability also.
The big thing is no expensive electronics to wear out or have to replace with the old gals.