For one, investment into open source software is always paying back: No matter what anyone else does, you will always at least get back what you invested. As an example, several public departments needed to improve Microsoft Office support in LibreOffice/OpenOffice. Not a single one of them could afford the CHF 50,000 which this would cost. But all of them could.
Another important point is that OSS never goes out of maintenance. Sure, there are many abandoned projects but that doesn’t stop anyone from taking the source and continuing the work. By definition, no one cares about an abandoned OSS project.
If you need help with OSS, there is a directory of companies which sell support: http://www.ossdirectory.ch/