I want to replace an aging fisher turntable and thought that a linear tracking unit might be interesting to try. I will be buying used on Audiogon or eBay, but this is a new area for me. What are some of the things I should watch out for? Should I avoid them altogether? Are there any makes/models that I should look for or avoid?

I'm not an audiophile when it comes to phono (most of my records are old and somewhat scratched), but I would like to have a good quality TT because I do copy records to CD regularly. Thanks.