The models I've seen from Dell and Lenovo with 4k screens and 64 GB ram tend to be in the 2500 EUR range.
And, for some reason, you usually can't get this much RAM and a 4k screen with an AMD CPU.
HP has EliteBooks with upgradeable RAM (both slots!) so you could do your own upgrade, but you'd have to put up with a ridiculously crappy screen. I also don't know if they've upgraded to ryzen 6000.
They have, I'm typing on one. The display I have is crappy BUT they have four or five different displays in the 14" 16:10 format and swapping one for another is relatively simple.
On my Gen8 model, I have the "high-end" display. It's admittedly very bright, but the colors and viewing angles are terrible. Some say it's because it has the privacy screen. That may be the case for the viewing angles, but the colors are atrocious even judging by the specs. At work, they have no privacy screens and colors still suck. At best, you get something like 72% NTSC (which is smaller than sRGB). The Gen9 models I see on their French website have a 16:10 ratio (which, I think, is great) but only... 45% NTSC!
Laptops with similar specs and features (minus coreboot) are available 25% to 50% cheaper from vendors that care a lot less about Linux support.