I run a small startup called SEOJuice, where I need to crawl a lot of pages all the time, and I can say that the biggest issue with crawling is the blocking part and how much you need to invest to circumvent Cloudflare and similar, just to get access to any website. The bandwith and storage are the smallest cost factor.
Even though, in my case, users add their own domains, it's still took me quite a bit of time to reach 99% chance to crawl a website — with a mix of residential proxies, captcha solvers, rotating user-agents, stealth chrome binaries, otherwise I would get 403 immediately with no HTML being served.
Even though, in my case, users add their own domains, it's still took me quite a bit of time to reach 99% chance to crawl a website — with a mix of residential proxies, captcha solvers, rotating user-agents, stealth chrome binaries, otherwise I would get 403 immediately with no HTML being served.