I am planning to build my own desktop this year. I built one desktop before in 2015. I staggered the purchase of that build's parts a little bit, over three months. But because this new desktop I'm planning is very this year, instead of the already past it (two year) Haswell components I was using in 2015, I'm going to have to save and buy at once, or stagger and save when there are sales. I was thinking July's Cyber Monday might prove to be a value, but maybe not. But if I were to buy parts one a time, I figure it would be Case > PSU > Motherboard > Cooler/CPU. I am supposing that the NVME and the RAM could be bought in any order as long as it is under a year because of warranty. I am wondering if there is any way to test a case by itself. I am thinking that it is likely I would at least have to get a PSU to test the case, but I guess really it needs a motherboard too? Or then there's the reverse strategy, that the case is actually the last component needed, because one can make a functional computer by assembling the components and setting them on the motherboard box.