If you go s21,or s22.
Only thing being is they’ll have done a lot of charge cycles and you won’t know how many.
So maybe budget for a battery at some point.
Also to make my phones last I turn on the 85pc protect battery feature and once a week let it go to 100.
Usually get a full day outta my s23u.
A rocket blower. Gently.
As used for camera lenses by photogs