I just bought a used pannier rack for my back-up bike. Turns out it'll be installed on the build for my wife to ride, instead.

Most of the summer I commuted only using a backpack because I jacked up the old pannier rack. I just recently fixed this, and I bought a used Axiom Hunter grocery pannier. That, along with my new Sunlite handlebar bag and the frame pack I bought at Goodwill for 99 cents, and I pretty much go without the backpack I used for most of the summer. I didn't mind the backpack at all, though.