Are old Opteron servers worth it for rendering?

I’ve found some old servers for sale, Opteron quad cord 2.7 Ghz, 8GB ram, in rack mount case, full working systems for $50 ea. I’m tempted to buy them just for the cases… but is the hardware worth trying to use at all with Blender 2.8+?

I guess the factor would be cost of power consumption vs cost of credits at a render service vs cost of power for a newer server for the same amount of work?

The servers would be for render work, with the actual file creation on my desktop, so graphics card doesn’t matter. Four cores isn’t a lot. But I’ve also seen old 16 and 32 core dual Opteron out there as well as Xeon’s that are fairly cheap. Can you build something decent yourself from old hardware that’s more cost effective than later hardware or a rendering service?

Everything would be cycles based rendering.

These things have a really low performance and very little RAM.
Apart from that, server hardware usually runs super loud (usually audible through multiple regular houses closed doors). Also setup can be complicated.
A friend of mine ran multiple IBM X3850 X5s. They roughly have the performance of a 3900X per node but can come with a lot of RAM pretty cheap. Nevertheless, I would not want to ever have something like them running in my apartment…