How much money should I take to Vegas to have a good time?

I’m trying to save up some money to get out to Vegas with a group of friends sometime during spring break.

I’ve never been, and am not sure how much I should plan on spending while I’m there.

I may stay on a military installation for the cheaper rates of a hotel, and I am looking into taking a military hop to get there for free…but at the moment I am going to plan on paying for a flight and hotel. I’d probably split hotel 2–3 ways depending on who all goes.