Hello,
I have created a quick prototype of your project, without including the payment part.
The id of the bot demo in telegram is @StoreFrontDemoBot. I believe that I am able to carry out your project successfully.
Another of my projects, more complex in functionality, in current development is @classifiedsBot.
If I am selected for the project, I would like to get a milestone for $ 20 for the advance made in the prototype and another milestone for $ 30 when completing it.
I will answer any of your doubts.
Thanks