My top pick for a Linux laptop would be the Dell XPS 13 9310. It's old I guess, from 2020. But the build quality and Linux support is excellent. You could get a used one from eBay for around 400USD.

Alternatively, maybe you could look for a used Thinkpad X1 Carbon. I've purchased several of those in the past and have had really good experiences with them. The hardware is great and the software support is excellent.

I would avoid Framework. I actually just switched back to the Dell XPS 13 9310 after a year of using the Framework. Linux support on the Framework is just not as good as some other laptops. The biggest con of Framework is the HiDPI display. You will never get the display to look good. You'll have to do a ton of tweaking and debugging—and you'll still have some apps that are blurry or have weirdly sized icons or text. See: https://lemmy.today/post/22761155/13770242

https://kfocus.org/spec/spec-ir16.html this is an absolute gem, built just for linux. It comes with KUbuntu preinstalled but can be wiped and replaced with any flavor of linux, and all of the hardware and laptop functionality is fully supported by linux.

Framework is way overhyped and even more overpriced. Its "upgradeability" is totally unrealistic at best, scam at worst. Sure you can pop in a new USB port or display output, but that's about it before you're replacing the entire guts to upgrade it and keeping just the worn out case and screen...? Gee sounds great... Repairability is a real point for framework though. Can you still not update the BIOS on linux? Its linux support is historically not great but may have improved