I can assure you that they are not hosting for free because the cost is zero and goodwill pays the bills. Read the TOS and privacy policy. If they’re not monetizing the data in their custody then it’s just more overhead that has to be covered by paying customers, which makes the business even more difficult.

Yes, you can host a repository for less than $10, but that’s not the question, is it? Can you host it cheaply enough that a customer paying $10 is a viable and worthwhile business? Can you do it for $5 all in with infrastructure, staff, and general and administrative costs? You won’t have much for a marketing budget so you’ll have to offer those free accounts with some features for viral network growth. Oh, and you’ll have to offer better uptime than GitHub. Still sound like a good idea?