I am looking for a way to limit the quantity sold of my product (to promote exclusivity). Since I am using Printful for fulfillment I can not use inventory count to do this. I am looking for and option that allows me to limit based on sales of said product. If I set sale limit to 100, then after 100 sales of that product, the product will become unavailable for purchase. Is there an app or setting in Shopify that will do this for me? Ultimately I'd like to be able to tie this back to some sort of visual relay for the customers on my products page that counts down how many orders have been made/left.