I know the github guys are on HN, so I'd love to hear how they arrived on those prices. They seem very reasonable if not cheap to me, and I'm very interested in the inside scoop.
In the end we decided the only way we were going to do it is by pricing it high enough that the enterprise world took us seriously, but keeping in mind that smaller teams want to use it as well.
I think the only way to do that is by charging less than Perforce, but far more than other solutions like CollabNet EE.
In Enterprise nowadays expensive solutions != better. It's the credit crunch :) managers are under the thumb to deliver working solutions for low cost.
Also explains why they haven't replied yet, they're probably hungover. ;)