Join Date: May 2002
Location: Pittsburgh
Programs: MR LT Titanium, AA LT PLT, UA SLV, Avis PreferredPlus, HH Gold, Hertz PC, National Executive, etc.
Posts: 31,670
Any economic-equivalent comparison is in post-tax dollars - you can't change your frame of reference just for fun.
If you believe your poutine for lunch actually "cost" you $7.14, instead of the $5 bill you handed over, and you make the same conversion for every item with a monetary value, then you can assume miles are worth 2.86 cents. I suspect very few people actually do this.
And in your original calculation, with a 30% tax bracket, the actual pre-tax cost is $428.57. It's not cost*(1+MTR), it's cost/(1-MTR).