With the most recent price increases in January, if you can find those three brands for less than $40 per pound, get what you need. The demand, shortages, and price increases have made north of $40 common.I would say anything Alliant, and especially Unique, are the outliers. Most Hodgdon/IMR/Win powders can still be had for $30-40 per pound. Alliant and their parent comapny Vista Outdoors have done it to themselves with steady price increases.
I have a few pounds of Unique, and that will probably last me a lifetime of .44 Special loading. I have found other powders more suited to most of the other calibers I load for.