Diy Mining Rack . The estimated cost to mine a single bitcoin (currently worth $11,962) is estimated to be about $4,758 in electricity. Building your own rack for a cr. First homemade (sorta) mining rig frame!! 30 shoe rack from Wally from www.reddit.com 25$ 8 gpu diy mining rack. Then you add 100w for the rest of the system* (motherboard, cpu, ram, disk) and multiply that by 1.2. Place a a rice grain size thermal paste on the top of the cpu.