Given the path that we followed from alpha-beta etc, usually stuff related to DarkSend were first tested on testnet to check them out for problems... I doubt RC4 will go online straight away as without testing it might break existing functionality. It's a 50mn coin right now, you can't just put large updates without test. But even when it was 1-2mn coin, we still went the testnet route first. So probably we'll first see a call for testing RC4 features, when some of these are ready, and then => RC4 announcement.

As for price, I recommend keeping some cash in reserve to chew panic sellers if something goes wrong. No matter how well tested it is, masternode payments are a big hack to the protocol and they may still present problems. This is not FUD, it's just the way it is regarding such fundamental changes. Let's say the right attitude this time round is "cautiously optimistic".