I’ve just been through the process you’ve described and bought a laptop. Your budget is way overkill for your use (documents, browsing, video watching).
I recently bought myself a “like new” second hand Dell Latitude (5300, I think), 8th gen i7, 16GB Ram for £150 and it is amazing with OpenSUSE.
I got my wife a new HP Aero 13 (Ryzen) a couple of years ago and even that was £580 brand new and has been great.
Consider the secondhand market. A lot of laptops will meet your criteria.