At companies where I've worked, all of the money we've put into open source has been in contracting the developer(s) to add a feature we needed to the upstream

At companies where I've worked, all of the money we've put into open source has been in contracting the developer(s) to add a feature we needed to the upstream version. Of course, this means that we didn't really fund ongoing maintenance on anything we used that had all the features we needed.