thats nice... thats what I want...
take advantage of low energy costs
you want these mother boards
https://www.ebay.com/itm/256419491752?https://www.ebay.com/itm/387259480958?I do not know the sellers
but I have a ton of six card boards and eight card boards.
look for low power gpus.
https://www.ebay.com/itm/235685338090?200-250 top price
look for 3060ti and 3070
right now you won't make a ton of money but just a small price pick up and the rigs will make good money.
A 3060ti makes maybe 20 cents
a 3070 makes maybe 25 cents with 1 cent power
if no one ships you the 6 and 8 card motherboards I certainly will.
the cards will pull around 120 watts with good settings so
a six card rig can do 800 watts which means you need 1000 watt good psu.
an eight card rig can do 1000 watts which means you need 1200 watt good psu.
also get a motherboard and just add a card at a time. don't go nuts.
Others will chime in and let you know what gpus are shit and what are good.
Avoid 3000 series nvidia with LHR if you can.