If you no longer want/need the social aspects of GitHub, you can just move to GitLab. Much more affordable and you can self host it yourself. We have an on premise GitLab installation. Besides the rare upgrade, it's pretty hands off. And it's costing us $0 in licensing fees for over 60 users ;-)
We self-host GitLab as well for ~20 users and are very happy with it.
We install every incremental update, which GitLab publishes very frequently -- weekly or several times a month. They are always seamless. The GitLab team is working so hard.
alternative, written in go and using way less moving components and resources is https://gogs.io It's lighter but also lighter in features than Gitlab.
I've always found VSTS to be at the same time expensive, bloated and missing essential functionality. I think the mentality of .NET / Microsoft developers is strange. By following Microsoft's lead, wherever that may take you, you're missing out and you don't even know what :-P
I'm a PM on VSTS. If you're willing to share what we're missing and what's bloated, I'd love to hear it. mattc@xbox.com or a reply here would be much appreciated. Thanks!
rare upgrade? They release every 4 weeks and often the update is absolutely mandatory due to various RCE vulnerabilities. Github would need to become much more expensive before it would be cheaper to use in-house gitlab.