I usually try and do some kind of cross-reference of repairability (https://www.ifixit.com/smartphone-repairability?sort=score) and Lineage support (https://stats.lineageos.org/)
Last time I got a Samsung Galaxy S5, does the job, easy to replace the battery. Can get for under a Β£100.
https://uk.webuy.com/search?stext=samsung%20galaxy%20s5
Rendering context...