I realize I am in the minority here, but I am going to side with Ingy. I usually don't burn miles for domestic awards, but recently faced with buying 4 tix PHL-DEN during ski season ($500 a pop) and a ticket PHL-LAS to play bridge in July ($500 if I took the red eye return) - I burned 100K miles and 25K miles and found it a good deal. OK I have 3MM miles and points "hoarded" (not really hoarding but I earn 'em faster than I can burn them).

Taking the family to the Grand Canyon next July. If I can find $250 tix I will buy. If they are $500 again, I'm gonna cash in miles and be happy to get 2 cpm.