If laptops already use it a decent chunk of monitors, even if they are laptop monitors, that would make it much easier to get freesync into desktop monitors. I doubt more than a handful of OCNers (if that) could explain the difference between the workings of the two, so as to their comparative costs/ease of implementation/effectiveness, that is still out to the jury.
But please, there is no reason to think G-sync is better because it costs more. As of now, it's only true benefit over "freesync" is that it is possible to buy now, and likely be the only option for a while yet.
What makes me excited about freesync is that the presumably low cost and implementation into existing/upcoming standards is that makes it much more likely to turn up in 4K IPS panels - and Oculus Rift.