I just read part of the thread, very interesting. Just went through buying a couple of refurbed i5 machines (HP EliteDesk 800G1 SFF i5-4570 and Lenovo M90P USFF i5-650) made sometime around 2013 and 2010 respectively. They both came with Win10 64 bit PRO installed on them (NOT ORIGINALLY... I can see by the history that they were both upgraded to Win10 sometime along from either Win7 or 8, and being both OEM channel machines they *DO* allow license transfers).
I needed to wipe them, put Win10 32 bit PRO on both to support a couple legacy hardware devices that only come with 32 bit drivers. I was able to transfer the licenses from the pre-installed 64-bit OS's to my installs of the 32-bit OS, so all is activated (as mentioned previously, it appears even OEM licenses can be transferred once but in this case hardware DID NOT CHANGE, I just needed to reinstall the OS and decided on 32 vs 64 bit - so technically shouldn't even register on the "transfer" count). Bummer is that even though both machines have 8 GB RAM, it's mostly useless due to 32 bit limit. But these were the cheapest "business class" i5 machines I could buy.
I asked the store if I could get the refurbs OS-less, but they don't sell any, which means I just bought 2 licenses from Microsoft essentially without needing them (as I could just as easily have activated Windows by pulling the licenses from the older Celeron computers these are replacing). NOTE: The older computers also run Win10 PRO and they are maybe 13 years old, no problems. The *ONLY* reason I even upgraded them is because they are pulling support from the current version of the proprietary software I am using, and insisting on everyone upgrading to the next version... and I need to meet minimum requirements of i5 machines. I can't refuse because this mission-critical software needs to communicate with 3rd parties as part of it's main function, and protocols keep changing so they make sure their software is up to date with changes. Otherwise if it was stand-alone I wouldn't care.
Personally I use LINUX at home and set up all my kids laptops with it. All on machines as old as these, or older. However, in my small office I need to run proprietary software that requires Windows networking and specific hardware that only works on Win 32 bit (due to drivers). So I'm stuck dealing with Windows. If it wasn't for that, I would be rid of Windows long ago.
I've tried to virtualize some of my office to some extent. Before I needed to upgrade to Win10, I was actually virtualizing a few WinXP Mode machines on Linux and they were playing nicely with the rest of the Windows machines in the office. The VM's had no problem running this proprietary Win-only software I am using, and also connected fine to the specialized hardware using those 32-bit drivers. I just gave the VM access to the USB ports and it ran fine. However, to put Linux on every computer in my office and expect my entire staff to work out of VMs running Win10 and expecting all to work efficiently (using SQLServer database within the VM that my Windows-only software uses) would be too much to ask.
So for now at least, I'll just have to work around all of Microsoft's B.S., until I find a replacement of my proprietary software that is either cloud-based or available for Linux. By the way, the cost to get set up with it costs $16,000 and annual upkeep which is mandatory is another $2500-3000, but so are all of the competitors too (none of which offer a Linux version as far as I know), and the market is fairly small so that's why they charge so much. Nevertheless, this mission-critical software helps you run your business so compared to all the other costs, it's really nothing for such an important role. And now that it has all of our stuff in it... it's a pain and costly exporting/importing data if you want to migrate to a different software package. Which means that it is still CHEAPER for me to buy a bunch of new computers that meet Windows requirements if I'm forced an upgrade, vs. changing to another specialized software vendor!