I've been researching this for about a month now (motherboards, GPU, PSU, racks, Watts etc) and ready to pull the plug on the Very Late just-getting-into-it.
I'm simply thinking about a single 6 GPU miner.
Of course, there are people on Amazon and Craigslist, etc selling the complete rigs (Talking ETH here, not ASIC) From what I can tell, these builders are taking a measly $200-$300 profit. Anyways, those units somewhat tempt me, as I'm having a hard time finding the hardware required in a short window of time.
Thoughts on 'aftermarket' sales of built rigs?
--edit-- Specifically thinking of security. Has there been any historical scams with pre-built miners?