After several months, the bearings in the cheapo fan that came on the cheapo heatsink that came on the inexpensive all-in-one mini-itx board have worn down, and the fan is making a whining noise. It's noise from an always-on file server that should be sitting quietly in the corner. Then I notice that the power supply could stand to be a bit quieter, so why not replace that fan, too? It's already out of warranty, so opening it up is no big deal. But wait, it's a low-power system, so why not yank the power supply out and go with a fanless 12V adapter with an external brick?
At this point, including taxes and shipping and all, I'm just over the $100 USD mark; that magic point past which I suddenly discover that I've just spent the past 2 hours surfing the web pricing out hardware for a new server.
I ordered the fans.