I'm sure there will be a next generation of jet drones that are cheaper, but the autonomy kit here is probably still cheaper than new jet drones.
I think most fully autonomous jet drone programs are also designed to work with a main crewed fighter jet that coordinates them, so there is also a benefit in getting the fighter jet to be able to fly better than a pilot.
They are already building them.
https://en.wikipedia.org/wiki/Anduril_FQ-44
https://en.wikipedia.org/wiki/General_Atomics_FQ-42_Dark_Mer...