I need a script (will run on web host) that will continuously and as efficiently as possible check an eCommerce site (not owned by me) for stock status of items and save the results in json. The amount of items will change week to week, it might be 10, 20, it varies. Some items have multiple sizes, some only have a single size. It will most likely need to support proxies because otherwise the script might get blocked. There is no api.
I will provide site, more details, and an example of something similar in private.