I’m in a different (but similarly expensive) part of the country, and the two closest options quoted about $800 and $1000. I opted to use the more expensive one because they had an exotics specialist on staff.
I would recommend talking to a vet in your area that specializes in rabbits/small mammals at a clinic that doesn’t do CT scans, and see where they would refer you to. You might also take this opportunity to get a second opinion before the CT scan. I’m not suggesting that your current vet isn’t doing a good job, but in cases where it’s hard to figure out what the root cause of a bunny’s issues is, sometimes a different vet is able to look at it from a new angle. An office visit and a look at the results of the tests your current vet has already done is a lot cheaper than immediately getting a $2000 scan, and might give you a better shot at finding somewhere that can do the scan for less.