Yes, a suppose anything is fixable for a price, and with time, energy and tenacity. My concern is for the budding enthusiast, struggling with replacing plastic gears is very difficult. Many models of Singer, once they especially went to plastic gears, integrated springs and levers that were disengaged once you removed to drive shaft and ancillary shafts related to the zig zag movements, etc. Re-engaging them is so difficult, at least for me, and then getting them timed properly that it becomes a nightmare. I have replaced plastic gears in the past, and though replacing them is doable the secondary issues related to re-engaging spring and timing mechanism was very very difficult. It sounded to me that Canadian Girl was looking for a relatively serviceable machine, so that is why I was so clear in my response.
I do agree with you though, of course, unless there are bent shafts that it can be fixed.. Whether the quality of the machine calls for is another question. Your mileage may vary...