So everything is about right. Today you can buy a budget pc, and skim on performance, but back then (and I was there man!) you could not.
In 1985 HDD were only starting to gain traction for PC's and that was about the only thing you could spec up. That IBM pc is "High Res" which probably means it was VGA multicolour (yay!lol) with 640x480 resolution. So you were basically buying top of the line.
Today, if you were to build a top of the line PC, RTX4090, latest best intel cpu, PSU, etc, etc it would be easy to spend $5K!
But damn, the difference in performance from back then to now!! (That IBM is an XT which means it was a 4.77Mhz with 8086 cpu. Just looking at that picture, I can feel the weight of the bloody thing)