Even cheaper than the LGA2011 platform, but with still good performance, there is the consumer-unknown LGA1356 platform. This one was designed as a low cost server/workstation platform, with a 3 channel DDR3 memory controller instead of 4, which may be enough for most of applications.
On Aliexpress, you can find LGA1356 motherboards at different prices, ranging from $45 for the Transcend X9AD or $50 for the Kllisre X9A or X79A (name varies) to almost $94 for X78 no name models, but they are all the same actually, with different colors of plastic parts (like PCI-E, DDR3 slots or SATA ports).
All are featuring 2 memory slots only (so forgot about triple channel) and most important, a M2 NVME ports with good performances !
I have one myself to test my LGA1356 Xeons and I was pretty impressed by the performance we can get for a such low price.
I bought on Aliexpress :
And I put the fastest LGA1356 Xeon of my collection, a E5-1428L v2 I got for $8, and here is the result on Passmark :
Tested with an old Radeon HD 5870, which make it more powerful than 65% of the submitted baselines on passmark.
The disk mark score is particularly impressive, better than 92% of the submitted disks :
Which is more than very good for a cheap 128GB NVME SSD on a LGA1356 platform which is not supposed to be compatible with it…
Memory mark is average, mainly because of the dual-channel only, but that’s fine for the price.
And the cpu, which is not the top of the line on this platform, reach nearly 9000 points, like a Core i3-9100F or a Ryzen 5 2400GE for example. The Top would have been with a E5-2470 v2, a 10-cores cpu that reach 12000 points, same level than an i7-7700K or i5-9500, or Ryzen 5 1600 on AMD’s side. But for more, for $100, here on Aliexpress. Or you can even go for a E5-2430, a 6-core cpu rated at 8300pts on Passmark V9, which you can get for as low as $12 here
A system at this performance level (just add a graphic card for your needs, gaming or not), for less than $120 with the 1428L v2, it is just unbeatable.
If you need some additional arguments, just look at the following video, where this platform is being tested on real gaming use.