Hi I’m in a similar position that’s how I ended up here. I’ll give you the benefit of my researches so far.
The old Xeon represents much better value. There’s a whole bunch of caveats, however.
The aliexpress boards use a recycled intel chipset that has been removed from old server boards. The Chinese are very good with electronics but motherboards are remarkably fickle bits of tech. They are generally branded Huanon zhi, plexHD, or other and can be considered generic. There have been different releases and to get best functionality need to be really careful- full speed nvme for example. There’s no overclocking except for unlocked multiplier releases (Xeon versions of i7 k chips), using throttlestop or similar:
Multiplier-unlocked Xeons according to overclocking results from HWBOT: Bloomfield: W3570 (source) W3580 (uncertain) Gulftown: W3680 W3690 Gainestown: W5580 (most probably not unlocked, despite of one CPU-Z validation; please see also...
forums.servethehome.com
Since these new boards have been released to meet a demand I wouldn’t be surprised to see increased overclocking options on the latest versions, one recent version has power boost bios settings. To get anything comparable to today’s performance on this old hardware you must overclock, but the best of those are still expensive even after all this time. (e5-1650 v2 is $90, 1680 v2 is $200). Alternatively, you could pick up an enthusiast board such as supermicro - ancient and expensive- for the X58, and a Xeon w36xx, overclock using the bclk method which is very productive for those. But so expensive, difficult, and still with a risk of screwing something. (Edit: Xeon 36xx series is unlocked, so could use cheaper locked chip on that board with that method).
So we are back at the beginning, accepting reduced performance for low cost. I’m currently in the bidding for a dell 5600 workstation. Dual socket but will fit a single Xeon such as the 2689. 800w gold psu with usb3 and expansion options, and four channel memory. Bought 32gb of 1866mhz memory for it already, £32 (about $40). Total system cost excluding gpu will be ~120$.
The ryzen would beat it in benchmarks for sure. But on a 1080p monitor they will be functionally identical.
There’s a lot more I could write but got bored of typing!
But still valid I guess.