I've done that, but...

At the end of 2008, for example, United increased the price of most international business class saver tickets from 80,000 to 105,000 miles. That 25K difference is obviously the price of a domestic saver! And Delta did a sleight of hand with its new three-tier scheme in which they vary the availability of the different "buckets". Others have done similar. In these cases, one has to act quickly to book several tickets at the new "old" rate (before the price goes up) as there is no juncture in these programs when a "deal" is more obvious. That's, ironically, "deal" vis a vis the new baseline. Even when there's a small devaluation, out over millions of saved miles, that will be several - perhaps many - free trips vanished in one swell foop.

Suchlike is inevitable. If you haven't felt like you've "earned" them in the sense of deliberately working hard for them, no problem. But if you have, there's one good word for it: "Amputated."

And there's another factor at work. The taxes and fees have been going up geometrically in the last couple of years. In particular, flying from/through London on a "freebie" has become terribly expensive. With some airlines such as BA, that charge their own "fuel surcharge" on award tickets, the era of "free" award tickets is over. Indeed, "free tickets" are now "award tickets".

[Parenthetically, and hopefully it stays so, a couple of airlines have shifted to a directly price-related earning and spending scheme. Meaning that not only are points earned in proportion to spend, but the redemption price in points varies according to the price of a revenue ticket at the same moment of "purchase". One never knows what one's earnings are worth until that moment. God help us. "Well, at least they're being explicit - explicit." (That echo is the income tax services...)]