Well, absurdely high isn't really true, it is quite similar to e.g. https://www.microsoft.com/en-us/windows-server/pricing

There is a some up/down depending on various rebates, volume licenses, support included/excluded, etc ("nobody pays sticker price"). But in general, RedHat is in the same order of magnitude as Windows but a little cheaper due to no per-core-pricing, no necessary CAL shenannigans or weird limitations on number of users/size of company/VM/PM and stuff.

But of course it's true that in domains like HPC or cloud computing, the huge number of licenses and machines involved make a few hundred bucks per year just too expensive in sum.