I would say that video game systems have gotten more expensive, at least the mainstream ones. There were super expensive systems back in the day like the 3DO and Neo Geo but even adjusted for inflation, the Super NES and Genesis were cheaper than the latest PlayStation or Xbox.
I think in the 8-bit and 16-bit days, pricing followed an odd trajectory. When I bought my first SNES games not long after that system was released I know at that time new games were typically priced at $49.99. At some point they went up (chip shortages or whatever). However, I think new game prices came down pretty fast also. That's probably true today too though I haven't paid much attention.
That is probably true because of the cost of manufacturing the systems. I recall reading somewhere that from about PS2 onward basically all system manufacturers sell their systems at near zero profit. I'm sure they are all pretty pissed about the fact that someone, somewhere, started this trend. I still can't really imagine the Atari 2600 costing anywhere near $700 (adjusted) to manufacture in the 70's though. But then again Atari couldn't really seem to do anything right and was the king of gaming only because they got there first.