I made an offer of £500 for nine of them. My calculator tells me that's £55.55 each

Looks like I need a bigger cpu

OK, I won that one. Bit of a background story for my decision:

1. I already have a Dahua starvis camera, and it can see in colour in the dark when I can only see dark. And that's with the IR LEDs permanently turned OFF.
2. These have the same starvis sensor, but are a ptz with a 4x optical zoom. They don't have IR, but are slightly more sensitive than my existing Dahua.
3. Dome camera, but no IR means no foggy image at night due to reflected IR.
4. I'm not going to chase higher resolutions, as the existing 1080 cameras are practically perfect for me.

But I hear you cry, don't you always say that ptz are a nice to have addition to a well placed fixed camera set up ? Erm yes...

I've been looking for replacements for my two analogue SD cameras. They use a PCI (Yes, Pci, not Pci-e) capture card which won't plug in to my main Ryzen server. I had found the DH-SD22204UE-GN and thought it fitted the requirements. They cost anywhere from £130 each upwards in the UK. I found them on AliExpress at around £80 but I don't believe the warranty would be any use unless you live in China. Search Ebay and nine of them in an auction that has been running for six out of seven days without a bid. Hmm...

So I managed to bag good quality ptz cameras cheaper than the fixed cameras I was reviewing. So much for logic.

Time to run some new network cables

And.... they all work. Excellent night vision, like my original Dahua cam, but with zoom.

It took some time. Initial setup with default IP address of 192.168.1.108 but I don't use that range. Then make a list of user/pw and new IP, then set up as H265 base and remove name/date/time - I use the BI5 timestamp for this as it no longer loads up the cpu - and running a ntp server on an isolated LAN was not amusing.

Now where can I fit them

Thats excellent! Glad they worked out for you. I know your pain. One of my go-to's keeps giving me offers to get extra free cameras if I leave a review (seemed very skeptical at first but it's actually worked out). I currently have 6 cameras waiting to be mounted in places but probably not 6 places to mount them. I've also been slacking on getting my ladder back. I really need to do that!