(Marco Cifuentes, another player who had some fantastic results in the covid era, consistently makes top 8 at major events in his home country of Chile, but hasnt travelled much outside of it, although hes played in Brazil in recent years, and I have to wonder if he would be hailed as one of the top players in the world if he was able to attend as many Regionals as players from other regions)
The reason that the Blue-Eyes White Dragon is less valuable is most likely due to supply and demand
And no, Ghostfire is not in Oath of the Gatewatch
There's also combo potential with cards like Triskelion: if you can first get a +1/+1 counter on Daggertooth then you can ping it with Trisk, proliferate both the Daggertooth and Trisk to add another +1/+1 counter to each, then repeat infinite times for infinite proliferate and an infinitely large Dino
In case you haven't seen them before, here's a quick look at some of their peculiarities