Here in the U.K. there are a number of machine dealers locally, but they never have the best prices. Once you have decided what you want, and what's a good price, you can do worse than fleabay! Most machines need collecting, so that limits buyers to local folks, and bargains can often be had! Generally speaking, the bigger the machine, the better value it will be!
Many amateurs don't have the space for a big machine, so that affects the used value. Big machines wear better too. I have seen many big machines with hardly any wear sell for very reasonable prices. Conversely, an elderly watchmaker I knew told me it took him years to learn that the only reason watchmakers sell their lathes, is that they are worn out!
Having said that, don't buy something that is too costly to move, or too big to work on alone!
Ensure that whatever you buy is complete. If it's a lathe, for example, ensure that it's complete with headstock, tailstock, crosslide, toolpost, chuck, etc! I know you can sometimes find these parts, but sometimes you can't, and then they need to be fitted! Accessories are different, and you can take your time collecting these, but ensure you have the basics!
Never buy anything with damaged castings or signs of abuse. I know castings can be repaired, but it's a lot of hassle and seldom worth it financially. If a machine has signs of abuse that you can see (burred screw slots, hammer marks etc) then there's probably much more damage you can't see, so avoid it!
Having got your machine, take your time and clean it up! Start by cleaning up the bare metal. Wire wool and machine oil can make an amazing difference to cast iron, and you won't damage it. Use engine degreaser or proper machine cleaner on the painted surfaces. If any paint is worn to bare metal I repaint (using enamel paint) otherwise I generally leave alone.
Badly rusted parts usually get a week's soak in Boric acid (No, it doesn't eat the metal, or anything else, just the rust) then a quick scrub with wire wool and oil! If there's still too much patina use emery paper, but ensure all the dust is blown out! Contact surfaces can be re ground easily - find your local tool grinder and he will usually skim the relevant bits cheap!
Re assemble using new screws if req'd, and set the machine up correctly. An original manual can be helpful here, but you can usually figure most of it out! I always have electric motors reconditioned as I can get it done locally and cheaply, and the insulation is almost always past it. I get replacement switchgear at the same time (the re con and switchgear usually leave me change from £60 if it's a standardish motor).
Finally, I'm not averse to making improvements. I generally have all hand wheels and scales chrome plated, whether they started out that way or not! Take your time, enjoy the job, and you may be surprised what your machine is worth!
