First, there are the costs of a game in relation to ones enjoyment in playing it. This is hard to measure, as it is an individual question. But one key factor in this is "duration of play". Imagine a game that you play for many, many hours, either by binge-playing it, or slow playing over a long time. We paid 60 or 70 Euro for Animal Crossing back then, but we easily sunk 1000+ hours into that game, as it is very relaxing and de-stressing after work. At 6 or 7 cent per hour, this is cheap entertainment. On the other hand, if you buy any title at AAA costs and throw it into the corner after a few minutes, the costs per hour are way worse.

Then: Some games take more development effort than others, and thus cost more. Whether the level of detail or whatever caused the increase in effort is worth it is another question.

Another cost-driving factor are IP costs. You can get a simple jump-and-run game for e.g. €10, or essentially the same game with Pokemon or Micky Mouse for €50.

In the end, if a game is too expensive, vote with your wallet and don't buy it. It's not an essential thing, it is just a game.