Hodgdon owns IMR, Ramshot, Accurate, Pyrodex, Triple Seven, Blackhorn 209, and White Hots. They also have some sort of license agreement with Winchester and distribute all of their powders. That is the majority of powders available in the US. The only powder they don't seem to have control over is Vihtavuori.
Yeah, one wonders about monopoly price gouging and even tacit collusion between Hodgdon and Nammo (owner of Vihtavuori). The optics are not good.
As a side note, that price for Varget is about what it is in my area. If you don't shoot black powder (or black powder substitutes) you'll be shocked to find out that the price of Blackhorn 209 is now north of 80 dollars a bottle. For an 8oz bottle!!!