Vaulting ceilings

[Kama Ward]

I've made an offer on a ranch house. If I get it, it will be my first ranch rehab. It could really benefit from vaulting the ceiling. I've vaulted the ceilings in small places before where it was easy and obvious, but never anything major. This would be over a 25'x26' area encompassing both sides of the ridge line. The roof is shallow, I'm guessing 4-5 feet higher in the center. It was built in 1961.

What have been your experiences with vaulting ceilings? What should I look out for? What's been your cost range? Any other tips for ranches?