Best cast recording of Sondheim's Follies?

I'm looking to buy a cast recording of Follies. However, I've been told that many recordings of this musical are incomplete. Does anyone know which one is the best and/or most complete? Also, does anyone know where any of these recordings can be purchased cheap? Most of the ones on iTunes are close to $20 and I'd love to save a little money if it's available cheaper somewhere else.