The idea looks great, but you might not completely get the kind of sales that you desire. You need to start up a shop that will help you make a profit, and at the same time, you want to promote crypto using that shop. That's understandable, but do you know that it's not just everyone that will like a product in your shop that will be a crypto user? The majority of people will like to pay with their fiat.
 
So I will advise that if you want to make a shop like that, add both your desired altcons available as methods of payment and also allow the use of your local currency for purchase. That way, you can be rest assured that your business won't fail even before you start it up. If the business has now gained some value and constant customers, then you can evaluate between those monthly sales and check which method was mostly used to purchase products from your shop. From there,  you can know the next step to take.