Please THINK a little, will you? What do you think Free Open Source Software is? If you have that much money to spare, you can buy all the support from FOSS solutions you need. In fact, you could even HIRE the developers to do your customizations, fixes, improvements etc; or use any other third party/company or individual you see fit to do the job.

The point with free software is the _freedom_ you obtain from not being tied to any  particular vendor or third partie. That doesn't mean you can't get professional services or support. In fact, it gives you the freedom to pick a different person to fix/improve any problems.

Should the commercial vendor go bankrupt or get eaten by a bigger company who later decides to kill the project; then you are doomed. With FOSS, you simply take the software to anyone who is capable to continue.

100k can do a lot of good to the FOSS comunity. Just think more carefully where is this investment going to do the most benefit. See Google, IBM and Canonical, for example...