The community would be in an uproar if such a sale happened. Reddit's only monetization schemes right now are 1) reddit gold 2) ads and 3) the gift shop. These are things that the community can completely boycott. Any sane person would know not to buy out something like reddit.
Reddit is really poorly managed. If Google bought it and gave it an overhaul I'm sure it would be welcome over the current administration. Plus, the "non-vocal users" simply don't care.
I would start with rewarding administrators with payment (akin to youtube, somewhat proportionally to views -- this creates a strong incentive towards fidelity), revamp post priority algorithms, and add some basic functionality that you need to install an add on (!), RES, to get (what other top 100 website needs this?).
A few hundred million for what -- a largely unmonetizable high traffic website full of tantrum throwing racists, bigots, and pornographers? They don't make much money from ads (they were unprofitable through at least 2012 afaik) and probably can't monetize that way -- even past the brand safety issues, it's still a forum that would feel lucky to get perhaps 50 cent cpm advertising on US traffic. I'd be shocked if they could clear 50 million, and that would be from someone who was going to fire the majority of employees and just run the site out. Particularly with digg's example of how fickle internet users can be.
I'm aware it was invested in at a 1/2 billion valuation, and good luck to them, but I stand by my analysis.
The thing is, 'reddit-likes' have definitively a place in the Internet, and I mean for the next couple decades. This format has been iterated over and over, starting with slashdot, 4chan, digg et al, and it's obviously one of the best ways we ever found to manage large discussions/news/etc. HN is an example.
Reddit is growing and would continue to grow really quickly. There's no competition in sight. Owning the discussion backbone of the internet is massively valuable, comparable at least to WhatsApp I'd say.
Can it die out due to massive exodus? Sure, but something similar will replace it. And for each iteration (slashdot,digg,etc), those websites have become larger and more consolidated. It's fair to assume at some point it will reach long term stability (particularly if it's properly managed).