Shoould my friends pay back?

Should my friends pay me back? I’m a senior and just graduated. So, three friends and I decided to take a trip to Panama City for our senior trip. We had decided it would be an all girl trip just the four of us. So we each put forth $150 to pay for the condo and had paid for it. The other day my friend told me she invited three more people. Her boyfriend and two other guys becuase hr birthday happened to be one of the days we are there.I said I was cool with it if they would get their own room becase the room we have is one bathroom and two twin beds so basically we are already bringing a blow up mattress to fit the other two. Well today I find out that it going to be 7 of us sharing a condo that has one bathroom and two twin beds while five of us sleep on the floor. They said its final because each of the guys are going to pay them $150 and it will pay for gas, food, and alcohol. Must I remind you we are 18 and I didnt plan on drinking. So I decided to drop out the trip . They said I already paid for the trip so I either come and enjoy or loose the money. I told them that just take $150 from one of the guys that they suddenly invited and pay me back. Should I get the money back? OPINIONS!