I got my 5650G on EBay for ~ $170 USD and the 5750G was previously > $300 but I noticed a few sellers at the $200 mark lately.
I put this into my server, its running 64gb of ECC memory and handles my transcoding and Jellyfin very well. Multiple 4K Transcodes and HDR support out of the box, while consuming as little as 10w to do so. Its the perfect media server platform as it checked off all the boxes.
dmidecode -t 17
Memory Device
Array Handle: 0x0030
Error Information Handle: 0x003F
Total Width: 72 bits
Data Width: 64 bits
Size: 16 GB
According to dmidecode it is properly utilizing ECC, my non ECC systems only show 64 total and data width.
I totally went on a guess if this would work as there is not very much 'complete' information on this build. As mentioned in the link you posted its very hit or miss. Since I have ZFS running on here, one of its soft requirements are ECC so I wanted to ensure I had it fully implemented or not.
I am using my old desktop platform on an Asus Prime Pro x470 with this memory. Its clocked at 2666MHz with some fairly loose timings (no XMP/DOCP, I kept timing stock). I was able to easily get it to 3200MHz with a slight voltage increase for some slight gains.
The G CPU's are not all dreams, I had to update my stable Debian's kernel to a backport and to use tools like radeontop or nvtop I had to compile them in manually as the distro ones are too old to read the Renoir based GPU. Outside of that, everything works great for Jellyfin running behind linuxservers docker container. I used the linuxserver/mods:jellyfin-amd docker mod on their jellyfin container and it worked right away. H264/H265 and HDR support all out of the box.
Its a great chip, I am very happy with my purchase. 4.2GHz all core with boost around 4.6GHz.