Tough in here this morning.
My wife and I had a Bentley Flying Spur and two stretch towncars for the wedding party. Half a day on a Satuday. I want to say it was around $3k but I honestly don't remember. The tip is almost always included in the price.
Call around and get quotes, then ask to go check out the cars before you sign, make sure they are clean and don't look worn out.