I would hazard a guess implementing this is cheaper for them than G-Sync.
Considering the amount of man-hours that display OEMs are reporting that Nvidia is devoting to helping display OEMs in getting G-Sync up and running, I'm not sure why people think it would just magically be cheaper for the display OEMs to do all the work themselves.
Why do you think it would be cheaper? The
only thing that people can concretely point to as far as what might be cheaper is any licensing fee that Nvidia might be charging. But given how much they're investing into getting G-Sync out in the wild, do you really think they're going to work backwards with licensing fees to drive away vendors? Right now they have vendors chomping at the bit waiting for their engineers to help them, and there just isn't enough bandwidth for Nvidia to do it all.
And there's a reason that's the only concrete thing you can point to, because
FreeSync doesn't exist, still. There is no solution yet, anywhere, by anyone. And until there is, until a display OEM actually implements it in a display, FreeSync will continue to not exist.