Throwaways from work were one major source of my home lab too. However for me this has become a lot harder in recent years, because our company scrapped its own

Throwaways from work were one major source of my home lab too. However for me this has become a lot harder in recent years, because our company scrapped its own datacenters and moved to the cloud. A hallway full of decommissioned servers is now extremely rare. We have some "computer rooms" left (not allowed to call them "datacenters" anymore) but it's just for the stuff that really must be on-site. Other than that, online marketplaces. Not eBay generally, because its auction system and international reach drives prices up, even for items which normally gather low interest. I tend to use local buy & sell websites where people usually offer lower prices than advertised and these kinds of items are not very popular so they tend to go cheap. I've never seen fanless servers, but my home lab is not something I keep running 24/7 anyway. And it sits in a dedicated room with my 3D printers and electronics workbench so it's not the kind of place I hang out for peace and quiet anyway :) It's my mancave really (though, for lack of a partner, right now my whole apartment is a mancave :) ). My 24/7 stuff I do pick for energy-efficiency and to a much smaller extent, noise. I have 4 NUCs for this stuff. 2 nice ones with 4/6 cores and 64GB RAM, and 2 ancient ones (one atom and one skylake IIRC) which are very low power though. They're the ones that keep running when everything switches to UPS. I'm not really big into networking so I have some semi-managed TP-Links that bought new for 35 bucks. They're gigabit, 8 ports and can do basic stuff like vlans and mirroring which is all I need. I'm not doing any CCNA stuff or anything.