The experience of taking kids to go shopping

My little son loves to go shopping. He is excited to choose products that he wants from the supermarket. He puts everything he wants in my trolley, and it's like they are free. I usually put things back on the shelf behind him. Thus, I am busier and more tired than a shelf stocker in the supermarket. Then, I told my little son that he was forbidden to go to the supermarket. He looked at me blankly.

Mommy: Do you want to go shopping anymore?

Son: yes. Mommy.

Mommy: You can only choose one thing from the supermarket at a time; otherwise, you will not be allowed to go shopping.

Son: Ok. Mommy.