FWIW, I drove from NJ to Salt Lake at the beginning of June. Toyota Highlander Hybrid with roof top box - trip cost about $800, primarily gas and tolls as I only stayed one night in a hotel (I had intended to stay another night but there were no vacancies.) There was a ton of road construction and roads in some areas were actually closed due to high winds.
Regardless of the car/SUV you choose, be sure to prepare for emergencies and car problems - i.e. make sure that you have extra water, blankets (it can be cold at night if you need to stop for a few hours), antifreeze, oil, etc. Know how to get at the spare tire and tools (AAA isn’t always near by and cell service can be sporadic.) Also, be sure to keep at least 3/4 tank of gas at all times because you never know when the next working gas station will be - there was a power failure in one town so all of the gas stations were closed.
Good luck!