ROI calc isn't going to net out, but still worth it from a fun/learning perspective. Used100Th/s S19j Pro from @Kaboomracks: $823 (divide by 3) Loki Duo + S9 psu: $50 combo promotion from pivotalpleb.com Vonets wifi dongle: $26 6" inline fan: $30 10"x3.5"x6" fan duct: $12 SC6-6 crimp lugs to mod S9 cables: $10 16 gauge psu cable: had one lying around 14 gauge power strip: same Lots of duct tape