Proxies are a necessity for any bot or tool when scraping or trying to purchase something from a website. Proxies allow you to run more tasks, decrease the odds of being banned, and have a faster connection to most websites (while using a server).
A proxy essentially makes you look like a new person for each task you run. Running 100-1000 tasks gives you 100-1000x the power to do any task you would normally attempt to do in your own browser.