Actually, that's exactly what Nvidia should be doing if it wants wider adoption of its tech to lock in gamers into an "Nvidia echo system". All the R&D is already is a sunk cost, and marginal cost of producing the pcb could be shared with the display panel maker, or just thrown in without any monetary cost to the panel makers. By keeping the cost of the panel same as it would have been for the consumers without the Gsync module, it makes for a no brainer purchase when comparing like monitors. Nvidia wins by selling more of its gpus that are compatible with the Gsync capable monitors, and makes its customers stickier as these customers would be unlikely to leave the "Nvidia Echo System" and would be reluctant to make the switch to an AMD card, even if AMD came out with a slightly better performing gpu.
At least, this is what I would do, if I were Nvidia.
Now, as a consumer, I know that echo systems exist for the benefit of the seller ad not the buyer, given all things being equal. Thus, I hope that the roll out of the adaptive vsync standard can be accelerated so that it can gain wider adoption quicker for the benefit of all gamers, and not just gamers tied to a specific brand. In the end, I (as a consumer) only care about me, and this would hopefully translate into sustainably more competitive pricing for all displays with this "feature" or capability included as a standard, rather than a premium option.