For those prices I could buy an old PC to do out of band management and have over half the money left over. The appeal of JetKVM/NanoKVM is they're price competitive with an extra PC for a tiny fraction of the physical and power footprint.

For feature parity, the old PC will require USB OTG, HDMI input, wiring for ATX control, and a software stack.

Sipeed makes a PCIe KVM card for around $80 that drops into standard PC cases.

I'd assume it runs off the 5v standby power when the primary ATX supply is sleeping. =3

https://github.com/sipeed/NanoKVM?tab=readme-ov-file

A pi4 is $35 + parts, and can do a PXE server as well... but it is the OS/kernel upkeep that always hits proprietary devices.

Small recycled PCs can certainly work too, and reminds me of the https://guacamole.apache.org/ project. =3