You set $250 as "Rig Cost" to any rig. But this cant work.
Each rig needs Board, CPU, Ram, SSD (or Stick), (OS), (other Licences), Risers, (small parts like Fans, Box, ...), which are fixed costs. BUT you also need PSU's which fully depends on the GPU load.
A 2080 Ti Rig needs a 1600W PSU (1300W with PL < 100) or 2-3 smaller ones, but doesn't matter in terms of costs. A 1660 Rig can run with a 750W PSU for just 1/3 of the price of the 1600W. So your calculation needs a bit more improvement here, which will change your order.
Yes, you can build a "mining" rig, without GPU's, for Sub-$250, at least in the U.S.
I'm not building Gaming/mining Rigs - just straight mining rigs.
CPU: Intel - Celeron G3900 2.8 GHz Dual-Core Processor ($41.15 @ OutletPC)
Motherboard: Gigabyte - GA-H110-D3A ATX LGA1151 Motherboard ($58.39 @ Amazon)
Memory: G.Skill - Aegis 4 GB (1 x 4 GB) DDR4-2133 Memory ($20.98 @ Newegg)
Storage: Kingston - A400 120 GB 2.5" Solid State Drive ($19.99 @ Amazon)
Total: $140.51 + $70 PSU + $20 Open Air Mining Case + $15 6-pack of Risers= $245.51
Totals ~$250
Couple of weeks ago I bought two B-Stock EVGA 1000w PSUs for $70 each. And I can run up to 6 GPU's on a 1000W. I wouldn't use 1080TI's, 2080's nor 2080TI's due to the low ROI, but if you did, you would have to spend a bit more on a beefer PSU. Or spend $50 on something like this 1500w
https://www.newegg.com/p/1HU-004W-003W6?Description=mining%20psu&cm_re=mining_psu-_-9SIA7GT7942441-_-ProductIt helps if you check around for sales, and if you not worried about buying on Ebay, New-old stock can lower costs too. I'll keep an inventory of parts, stocking up when I find a good deal.
BTW - Windows is free from the Microsoft website - you just don't activate the license. Saves a couple of $.
I know all of this works - I've been doing just this for a while now - no problems.
Additionally - I've bought "New" old stock on Ebay - recently got a mining MB and Processor for $50 - Both new.
