Online shopping with proxies opens what is unavailable from your region: local discounts, products absent from local stores, services with regional prices. Proxies for shopping — an address of the country where the store works.
For example, a proxy for Amazon lets you see prices and offers of the US store. Or local sales visible only to residents. It works for ecommerce platforms too.
Important: some stores block purchases from proxies — especially from datacenter addresses. If you hit a block, take residential addresses.
And do not forget security: pay only over protected connections and do not store card data on sites you visit through a proxy.