Definitely look into Las Vegas Advisor. Purchase multiple subscriptions (you will have to have friends buy online, or bring them into the office with you). Stay downtown and take advantage of lower prices on both food and hotels. Savings will let you rent cars if you feel that's neccessary. Buy show tickets at tix4tonight, locations all over town. Start using MyVegas to accumulate freebies. Have your friends do the same.
Best lower-priced buffets: MSS, Orleans, Palms, anyplace with "Station" in the name. Definitely visit Ellis Island. Good food and cheap drinks. Coffee shops are often better options than buffets