Well I spent 620€ for build with no PSU, SSD, dvd included because I have a lot of this spare unused parts. For GPU I will use GTX 1060 which will be 300€ max, so I hope that this build will be 920€. I found whole new AMD PC with case psu, hdd, dvd, everything (no OS) for 120€ in local computer shop with 2 years warranty but I think that it is not so good as this dual Xeon, and maybe I do wright building this although it is almost 10 times more expensive and much bigger case.
I usually use PC for gaming, internet, doing software, sometimes for virtualization and test applications I made, doing electronics, programming microcontrollers, doing HD home videos. Rarely I use 3ds to do some rotating text or simple animation. I haven't been in 3d since 1995, till then I made a lot of commercials and animations in DOS Autodesk 3d application (does anyone tried it? Shaper, Loofter... and so). So no heavy duty work, but I think that having such machine is not bad.