For me, everything is on the table for used with a minor exception for spinning drives which I tend to buy new. There are some good recycling companies out that that have killer deals on enterprise setups. A lot of those also have enterprise activated idracs (dell hardware anyway)for example which saves me time running up and down stairs trying to get it setup or investigate why I can’t ssh into it.

For example, I picked up a dell 720xd from a recycling company for $450 shipped - 256gb ram, 20 cores(40threads), enterprise idracs, 12x4tb sas, and 2x 300gb ssd for os. Is it louder than a setup I could build, absolutely. But I needed something to replace my Amazon drive for my photos and this was way cheaper than adding 10 more drives to my main nas setup(I would have done >14tb drives in there)