Depends on how you calculate costs. Like, I have Kodi running on a RPi for home entertainment/theater. There's no way to outsource that, but the RPi is idle most of the time. Adding services to it is effectively or marginally free, except for my time, and there's still a significant time cost to get paid, off-site cloud services set up.
But charging for your own time is kind of disingenuous. You don't include your time in the cost of eating (a Big Mac worth $60??), watching a video, or going on vacation. The only people self-hosting have a personal, hobby/entertainment interest in it, and I think it's more accurate to compare the costs of self hosting with the costs of other forms of entertainment. Do you get more fun-value out of the costs of self hosting or out of a theater ticket?