The issue is the current GoGo systems are using conventional 3G internet connections. They are a victim of their own success. Way too many travelers use GoGo per flight now. They are currently upgrading to 4G, and that will help quite a bit.
The international system will use leased satellite space and I think they will eventually launch their own bird. I would expect latency to be worse on the sat, but overall bandwidth to be much better. No idea on pricing, as of late it appears GoGo has been using revenue management software and has variable pricing based on route/time.