I bought my Unimat 3 a few years ago on ebay. It cost me £160. I needed to replace the motor, and I bought several accessories, so it might depend what it has with it.
I should say maybe £200/250+ with all the tooling, or £150 for the basic lathe.
I am sure that it is capable of better work than my ability allows, but it is a little small, so I am looking to obtain a bigger one.
Regards
Geoff