Yeah, I understand that.

But, for purposes of this thread, you don't really value an upgrade as more precious than pearls -- at least in the sense that if I offered you $10,000 in pearls instead of an upgrade, you'd take it every time. You could sell the pearls, buy a first class ticket, and keep the change. I think the question in the thead is how to find that value where you'd be indifferent between taking the points and taking the pearls.