Hi Emma, Yes, I felt the need to have a back-up I got a featherweight that I'm loving!! It only does straight stitching but is just what I want to have downstairs or to take to a class. I would try the machine shop here and ask Billy or Charlee or Miz Johnny. There are many answers to this question.
Mine is to get something that works well and fits your budget.
PS. I love the older machines for a back up b/c they are well made and don't have lots of things that will go wrong.