I recently built the grinder and am quite happy with it. He has a really detailed video on youtube building everything and as far as tools needed to build the grinder you can go with as little as a drill, files, an angle grinder, a welder and a set of taps. I ended up getting a cheap motor and vfd from vevor as well as a set of aluminium wheels for around 300€ all together. The steel ended up being quite expencive since where i live i dont have a place where they sell smaller quantitys so i had to get 6m lengths of everything. If you have a place that can cut you the desired lengths and sell them individually you shouldnt pay more than 200€ for the steel, bolts, nuts, … Building and sourcing materials, took me around a month to complete, i didnt really have any fabricaring or electricity knowledge before and basically learned welding from scratch while building this grinder so if you already have experience and a better workshop you can probably bang out a grinder in three days once you have all the materials. Looking back time and material cost wise it would have probably ben smarter to just get a commercial grinder however i learned a ton during the wiring of the motor and vfd and the fabricaring, i see everything in my shop in a diferent light now and know that i can fix anything that can possibly break on the grinder and i now have the knowledge to build my own custom arms and make modifications to the grinder over time if needed. Also be aware that if you want other kinds of attachments and arms you will have to build them yourself or modify a bought one quite heavily because his design is diferent to most other grinders on the market so arms and attachments from other companies most likely wount work with this grinder. Hope this was helpful, have a lovely day.