I'm a functional languages fan, but I still use OO because it is useful. It's all machine code in the end, but the linguistic texture that gets you there is just as important (if not more so).
Over time, engineering talent and opportunity cost through being less agile tend to be way more expensive than the tool-sets you use unless you are at Face Book scale. That's just gut instinct, but please let me know if you think you can prove it. The reasons that make something a good choice for FB, might not suit you.
As tech people, it seems that we're often encouraged to be at odds with one another. That doesn't always need to be the case though. The F# Type Provider work is a great example of how technology can work in an additive and not a mutually exclusive way.
Free is not necessarily low quality, but free is never "free". Paying for a virtual team shouldn't be such a big deal if you are getting quality that would be time consuming, difficult, or impossible to acquire otherwise. There are some strange technical fashions in SV that I don't pretend to fully understand, and big companies still get their strategies wrong.
Going with a sales driven domination through mind-share strategy might not suit you medium or long term. Cool might not be "cool" for you. Just saying.