Potential cost of increased storage onboard the spacecraft if it is significant data volume. Cost of downlinking the data to the ground, time on the DSN is expensive. I think the cost data sheets for DSN usage are online and it depends on data rate, what dish you are using, etc. but costs for usage are on the order of thousands per hour and data rates from Jupiter are pretty slow.
The cost of the camera itself is likely on the order of a couple hundred thousand. I've seen similar costs for small radiation hardened cameras and star trackers. The difference in parts cost for some things can be absolutely insane. Passive electrical components certainly cost more, but for active circuits it can be insane. A radiation hardened equivalent of a $20 FPGA can be something like $20,000.
All told, cost of integration and use over the mission is likely at least a few million. But on a $1.1 billion mission it still doesn't seem like a lot.
Has anyone actually tried putting up non-rad hardened equipment to measure how they perform? The Mars helicopter wasn't RAD hardened and used off the shelf parts & succeeded and the Mars atmosphere is not thick enough to meaningfully block the amount of cosmic rays hitting the surface.
I think NASA doesn't do a good job sometimes tolerating risk and then everything is treated as needing safety-levels of risk mitigation without considering that a 1/100th cost reduction will not generate as much in parts failures.
https://news.ycombinator.com/item?id=39175423#39182421
Lots of the new space, and smaller satellite companies use a lot of commercial parts. A lot of the flight data has shown even better results than the radiation testing (possibly due to added stress of testing at higher rates vs low rates over longer mission duration).
Generally speaking most of this is in LEO with a pretty low radiation environment. Whereas the area around Jupiter is one of the worst radiation environments in the solar system due to the radiation belts (like the Van Allen belts on steroids). This page on the Juno Radiation Vault says the spacecraft is exposed to an anticipated 20 Mrads of radiation. Whereas spacecraft in LEO are exposed to 0.1-10 krads per year depending on the orbit.
Also a fun fact, this is with Juno trying to limit exposure to the radiation belts as much as possible. [1]
[0] https://en.wikipedia.org/wiki/Juno_Radiation_Vault
[1] https://en.wikipedia.org/wiki/Juno_(spacecraft)#/media/File:...