You can also get cash for "free". Examples: CapitalOne has "Hassle Free" rewards and Chase has the ability to switch. Some cards w/ the ability to be fluid will give you bonus cash for signing up.
Cash redemptions are usually one of the worst ways to redeem points. You can put a dollar value on your points by dividing the price of the flight when you book it by the number of points it cost you. 1 cent per point if you choose cash vs 2 cents per point for miles usually...