i would buy it, but i miss swamps,canyons,tundra and jungles biomes.
And an higher variation of mountains and plants for each biome.
Many Gamemasters would kill for an complete Overworld Asset pack to visualise their Overworld in Tabletop RPGs.
for hex based assets we all use http://dgbaumgart.com/works/painterly-game-tiles-hexes/ stuff because it has an high variation and he is working on new stuff right now.