The value of a mile is indeed subjective.

For example, say a trans-Atlantic ticket in Y costs $1,000 and a J ticket on the same flight costs $6,000. Suppose I can also upgrade the round trip for 50,000 miles. (I picked these numbers to make the arithmetic simple. Plug in your own if you want.) So the "value" of a mile for the upgrade is 10¢.

Except that it's not, because no way would I pay $6,000 for that J seat. As far as I'm concerned, and as far as the value of my miles is concerned, that number is irrelevant. It could just as easily be $60,000 or $6 million - I still wouldn't pay it, but if it was $6 million, would my miles be worth $120 each? Of course not.

I'd pay more than $1,000, of course. If I'd pay $2,000, each mile is really worth 2¢

So far so good, but if I'd pay $2,000, there's someone else out there who'd pay $3,000, so her miles are worth 4¢ each, and there's a miser who wouldn't pay a penny over $1,100, so his are worth 0.2¢ each.

And that's just for this purpose. It's not as if trans-Atlantic upgrades are the only thing we use miles for.

I try to use my dollars where they bring me the most subjective, not financial, value. Ditto for my airline miles. Since my options for using both are different from yours and my priorities are as well, my uses will similarly be different.

So any attempt to figure out "the" value of a mile is doomed to failure. There is no such thing. There are many values to a mile - yours, mine and the bloke down the block's. An average makes as much sense as saying the average family has 2.4 children - perhaps true in a mathematical sense, but I have yet to see a family like that. That's one of the things that makes this game interesting.