Walmart has Kiera Grace Priva 7" Corner Shelves, Black, Set of 2, $5.49 + free pickup.
Corner shelf with black finish
Set of 2: each shelf measures 7-3/4" x 7-3/4" x 7-3/4"
Holds up to 8 lbs
Some assembly required
Hanging hardware included with black corner shelves
https://www.walmart.com/ip/Kiera-…2/45825082