Within your pay command, you have a function set up to deduct a specified amount of money, correct?
You could create a straightforward paginated embed with Discord pagination (or something similar) to showcase the pricing in your shop command.
Next, establish the buy command. This involves checking what comes after the buy command - consider assigning unique IDs to items in your shop and including them either next to the item or within its description in the embed. When a user triggers the buy command, verify the ID provided.
If no valid ID is found in the arguments or if nothing is specified, return an embed notifying that the item was not located; prompt users to use the prefix along with the shop command.
If a specific item is mentioned by the user, proceed to deduct the purchase amount from their database using the pay command function. Afterwards, add the item to the user's inventory stored in the database. :)