From the impression I get, if your growth is big enough that you need multi-site replication (I'm sure there are outlying cases where you are a small company and need multi-site replication, but those are very rare instances I would think) you're going to need more than just "something to install".

I think Basho has a ops guy that is tasked specifically with going to these Enterprise companies and helping them with the setup - multi-site replication most likely means there are hundreds or thousands of nodes being deployed and that type of thing is really complex and also tricky to do right (even with Riak, which makes it REALLY easy).

My feeling on the price issue is this: Riak is willing to work with their clients - if you need it, you're going to call them and they basically workout what it is you need and what they can provide (maybe it is just the multi-site addon, maybe it's that plus a ops guy that knows Riak in and out and can get you completely set up worry-free with full-time support).