I’ve got 8 dell r630’s, hp dl380 g9, and 2x 2u 4 node supermicro chassis all running e5 v4 CPUs in my lab. Still supported by the current build of VMware, they run great and are relatively power efficient. I do have 4 Xeon gold servers, however I havnt even fired them up because they aren’t much better than the v4’s (only v1 scalable) but I probably will eventually when VMware ups the hardware requirements.
I don’t know where you are at, but in most countries with eBay or probably anywhere else, buy the server barebones, or with really low spec components (low ram and even v3 CPU’s) and upgrade it yourself. I find this to be a lot cheaper than buying it prebuilt with identical specs.
For example, my dl380 g9 came with a single v3 Xeon, I bought a 12 core e5 2650 v4 for literally $4.79 shipped to my door. Flashed the new bios and I was off and running. I also can pickup as much ram as I want for ~$7 per 8gb ddr4 dimm or $12 for 16gb dimm on eBay all day long (us prices obviously but it still should be cheaper to buy low spec or barebones outside the Us and upgrade)