to straighten a frame. how much?

[primetime]

i bought a 1972 c10 lwb, by the pics my wife sent me it might be better to replace the frame with a shortbed frame instead of treating the frame and replacing indiviual parts. we both like the shortbed better. through the miracle of internet theres a 1967 and 1972 c10 i can get from nc for cheap cheap in NC. the guy says that the 72 has frame damage. what is the price range for having a frame straightened? then again, will it be so bad to use the 67's frame? both are swb stepsides.