Not a good solution. Coop, Lidl etc. have solved it much better.

Max, the worker
Goes to buy a sandwich and a drink at 9 o'clock. 9 francs
At 12 noon he goes to the counter to buy something warm 12 francs
Doesn't score any points.

Grandma Anna
Buys a few things every day. A bread roll, some fruit and something small to eat. About 11 francs
Son Anton goes with her on Saturday. He buys some mineral water.
About 18 francs
No points again.

Housewife Sandra
Buys 98.70 on Friday.
Gives 4 points. But could also get 5.
Buys bread and fresh vegetables every day for 8 francs.
After a walk, the children want a sandwich and an iced tea.
6 francs
No points

You spend so much money and get nothing.

Too bad