The Co-op and Migros at the train station are the only shops open here on Sundays. Unless you really need food don't bother as they are significantly more expensive than their other branches in the city centre.
Honestly, Basel is at the top of my list of favorite places.
It is open and friendly, and really clean! I love clean air, clean streets and privacy,so I love BASEL!
Because it is near the Rhein and down town (at least 5 minutes by walking) it is good hotel for staying in basel.