Man, talk about over-thinking this stuff. While I agree with the basic premise and we all do this type of calculation, albeit imprecise and at a visceral level, when we decide what to allocate our limited dollars on, I think reducing it to a formulae would produce to many outliers and unexplained deviations from real world and entrenched opinions. For instance bvscfanatic's coments about proof bring up the question of overall flavor intensity and how that relates to things like proof off the still and barreling proof and level of chill filtering, if any. Case in point, I like Booker's. Many would say that Beam Black has a nearly Identical flavor profile. But as Chuck has stated elswhere, Beam now, and for some time (?), has distilled to brand, meaning that what is designed to become Booker's comes off the still at exactly 125* and goes into barrels at 125* while what is to become Black Label comes off the still a bit higher ( I can't remember the number that Chuck cited) and is watered down to 125* for barreling. Putting aside the "chill filtering factor", surely, this results in a diference in flavor intensity (when watered down to the same proof) even if the flavor profiles are esentualy the same.
Not taking these things into account may give whiskys like WT a disadvantage when put against brands like OF which comes off the still at a much higher proof.
But I admit, I haven't went through the math. I just like to drink the stuff.