To be fair, the crowd that AMD is trying to target this at out aren't in it for the 'bang for buck'. That's not what the 'halo gaming' market is about. Think 3090 Ti owners here. They just spent $1500 on their GPU to gain 5% over a vanilla 3090, so spending a bit more (or less) on a CPU doesn't really matter that much as long as it is the 'fastest'. Trust me, I've seen enough 3090 Ti owners out there to see that most run 12900K or 5950Xs, CPU pricing isn't a concern for them. I do wonder if most 12900K/5950X owners would be tempted to 'sidegrade' to a 5800X3D just to get a few more fps though? Personally, I wouldn't, but I'm not just a gamer and use my PC for work as well, so I'll take 'moar corez' thanks
Also, I don't wish to derail this thread, but as an 12900K owner those 'headaches' with the 12900K aren't really true - for gaming, heat is a non issue, and I actually prefer having the E-cores to be available for background tasks while I game. RAM tuning? I think most people just set XMP and that's it (until recently I was in that camp too, the gains are small even with tuned subtimings). You may be exaggerating for effect, but honestly, I encountered none of those issues with my 12900K WR to gaming.
FWIW, DDR4 can still be expensive if you go for the high speed / low latency stuff. For my 12900K, I went with Trident Z Neo 'B-Die' 3600 C16 which was approaching the price of DDR5 kits (albeit entry level), and my DDR4 kit isn't even considered truly premium like those DDR4-4000 kits. Yes, when comparing fast DDR5 vs fast DDR4, DDR5 is obviously more expensive still, but I do see the prices trending down slowly for DDR5.