I don't think I would pay for any of the core features, but that's mainly because I've been using Docker for 5 years with the current strategy of just about eve

I don't think I would pay for any of the core features, but that's mainly because I've been using Docker for 5 years with the current strategy of just about everything is open source. You pay if you want support and other enterprise features. Private hub repos are also reasonable to buy for most people because it's priced pretty competitively with rolling your own private registry on a cloud provider (ie. $7 / month for 5 repos isn't much more than $5 / month for the cheapest DO droplet but now you need to manage that machine yourself which is not worth the hassle for $2 less).