How to create a database for a store aggregator?

Question

Database design

The meaning of what I want - Yandex.Market
We have ten drugs
We have four pharmacies
Each pharmacy sells at least one drug
Each pharmacy has its own price for each drug
The end application gives a list of drugs with a list of their price tags
I don't understand how to this build the database. Where should we write price tags?
I rush between "Price tags in the drug table" and "Price tags in the store table", and something tells me that both options are wrong.
If you can show an infological model, then it will be chic in general.