I always order mine direct from maker, Kingston or Crucial but noticed tast time i tried neither had stock as older models no longer fabricated so had to buy from amazon
Yeah - last time I bought RAM - was from an actual computer shop…
I have bought RAM on e-bay in the past and it was fine… The first pair of 16 GB modules I bought for my AMD system was on e-bay… And I bought a pair of 8 GB DDR3 ECC modules for my NAS (TrueNAS) was off e-bay and they work just fine and really are, what they claim to be!
But I probably wouldn’t risk it again… Having been stung by shonky USB thumb drives…
I had kind of wanted such a thing, but never bothered to pursue it. Then when I switched from Linux Mint to MX Linux, there it was – Conky, a desktop widget that (by default) shows time, date, RAM usage, and CPU usage, but can be configured to display other things as well.