a small 600x1000x200 mm has parts 3-4k., i thought my build 8x4 would cost me in parts 6-7k, it cost me around 9-10k. That for very good machine. and it will take a couple of months at least even if you work with plans.

Used machines could be a deal or not, the main problem with them is they could be to limited in something, too specialized. Or just to power hungry for a home workshop or even for a proper work shop. And problems and no support.

There is nothing better than custom build machine for your specific needs. And even with the basic training and support from the builder you will be far far ahead.