Noone knows what it will cost "you", they know what it cost them.
You have to figure out how much it will cost you, find out pricing for components in you local area, find cheaper shipping methods, methods to dodge custom, learn soldering and other skills you might need.
My ErgoDox at the cheap price didn't build itself, nor did I know anything about soldering before I built it, I researched, learnt, practiced and was patient. It took 2 complete months, but I was able to build a beautiful piece of computer peripheral at the bare minimum cost possible. And it even worked on the first try itself. Some items took upto 20 days to arrive, because I opted for cheaper shipping, as keeping low cost was the number one priority. I made multiple trips to areas of my city I never knew even existed, spent countless hours online searching for vendors, reading stuff on GeekHack, watching videos and what not. Heck, I even learnt CorelDraw just to edit keyboard drawings, and now I am pretty good at it.
For me, ErgoDox experience, was not just about getting or making a great keybaord, but the amount of knowledge and skills I gained transcend the end product.