it helps to have a good sewing machine - the difference between a poor quality one and e.g. a nice bernina is dramatic. even an old one thats been well maintained will give you many years of reliable use with minimal maintenance, and they're very affordable used
> even an old one
My overlocker was made in West Germany (when that was a country), and is still going strong.
Threading was a bit tricky the first few times, but the manual is really exceptionally well written.