Oh my god, this is magic - it took 10 seconds to install wordpress. I'm buying an account for my mom. It'd be awesome to know the pricing for the managed hosting!
Sorry, we spent so much time making the billing prompt a seamless part of the flow of using Sandstorm that we forgot to publish the pricing outside of that. You can see pricing if you sign in, go to your account settings, and click "change plan".
(It's $6/mo for the standard plan, which is probably enough for most people.)
Oh, but note that all plans are free during the beta period, which will last at least a few months. :)