Isn't your home lab supposed to make you learn stuff? Why would you leave it idle?
You wouldn’t, it’s given as a lower bound, it costs more than that when not idling
but then you’d turn it off, if you don’t then cloud is much more expensive too.
Also $150 for 100w is crazy, thats like $1.70 per kWh; it would cost about $150 a year at the (high) rates of southern Sweden.
Im not the OP, don’t know how they arrived at that cost.
Personally it’s cheaper to buy the hardware that does spend most of its time idling. Fast turnaround on very large private datasets being key.