<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by awness:
The actual price they show says "Price includes both Federal Excise Tax and processing fee" underneath it. When you take off the 7.5% and the original 2.5 cents this leaves an apparent 0.093 cents per mile processing fee!
So the answer to your question - neither!</font>
If you apply the excise tax only to the 2.5 cents price, not the 0.1 cent processing fee, it works out. But don't ask me why you should do it that way.