See, that's why it is good to have some FF miles in reserve. Both standard Y and BF awards are available for that flight!
But really, why is it so surprising? Last minute fare is always expensive. At least CO is offering you a "H" fare for $2,000 and not just a "Y" fare for ~$4,000. You're already getting a 50% discount, and you earn 150% EQM. What's there to complain about?