If seller can give a stitch sample I assume they are fine. I know plastic gears can crack, but at the right price the worst thing that can happen is repair or in for a service. A nice condition machine is worth it. With a bit of luck, all a fix up machine needs is a good clean up; I have only had my 730 and 900 Nova service a couple of times. I don't really recommend it, but they aren't used that much. I hesistate a bit more on very worn machines, but dirt, grime, staining from old oil and thread mess I can alway do something with.