Great as a publicity stunt. Kinda idiotic when it comes to implementation.
How many things are goin to cost exactly 0.01 or 0.05 BTC especially with a changing exchange rate every day?
If you are able to spend fractional sums, then the face value doesn’t match the wallet value any more.
What would be a lot better would be a bill-shaped hardware wallet with a large digital display that could show the balance. Add to that a fingerprint authentication and a qr scanner for 2 step transfers and now you have something.
Yeap! But this way the store owners had a nice marketing boost :D