I gave birth in St. Paul's hospital. Didn't think I needed a private room, but when I checked in they said a private room was available and I decided to go for it on an impulse. I thought it was really worth it... being able to rest a lot better, see baby whenever I wanted, and have my husband around at night. Sure, it was only for a few days and the bill did give me a minor heart attack (insurance ended up covering more of the cost than I expected), but all in all, I'm glad I went for it. Giving birth for the first time is a very special time, I think it's worth splurging a little for the experience.
Also, Sanatorium's semi-private room seems to be a good deal. At least the semi-private room my friend had was almost completely private (with a couch for husband to sleep on too), except having to share the bathroom with one other mom.