I don't remember any mention about cost. They are hoping to get multiple services in Europe and Asia so they have world coverage. They didn't mention trying to get other providers in the US to split the cost here, just that any brand of phone-Google, Samsung, Apple etc, would work. Providers that agree to support it have to section off a small subset of (what I am assuming to be) texting bandwidth, because it does end up traveling down and going onto the providers network, so they have to reserve the necessary frequencies.
Edit- Did a quick look, it was 12 days ago, and there are several videos on Youtube. Search for T-Moblie and Spacex. The original announcement was a 40 minute length, but there is at least one that is 11 minutes or so from CNET.