I don’t want to be jumping all over you, but the questions have already been answered in your other two threads.
Renting a car is better and cheaper than the limo if you’re coming from LV. You have more flexibility with your time at Sheri’s. Like you I don’t know how much ~30% of a party will cost, but I bet one or two days car rental is cheaper. Remember if you stay at Sheri’s overnight you may even get the hotel bill waived because you had a party. So you could drink all night and sober up the next day. Or you could do what I do and rent something special to make the driving part of the trip.
Just go to the websites of the major rental companies (Hertz, Alamo, Enterprise, Budget etc) and go through the process of renting a car to find out how much they will cost without actually hitting the ‘buy’ button. Prices can change daily BTW.
Some things to look out for.
CDW – collision damage waiver – extra insurance should the car be damaged during your rental period. Check the car before you leave it. Perhaps even take photos, remembering to include something that will timestamp it (like a rental employee).
Fuel levels – I always pay for a full tank so I don’t have to find a gas station near the rental return. They can be really picky about what a full tank is. Sometimes if it’s the tiniest fraction off they’ll charge you.
Don’t bother with hiring a sat-nav unit if you’re renting for more than a week. It’s often cheaper to buy a cheap or refurb’d unit from somewhere like Wal-Mart.