I don't know what to do! Help!

I currently have a huge dilemma! I need to buy my plane like ASAP before the tickets skyrocket but I don't know when I want to leave Europe yet. Oddly I have only found two other people out of the twenty that are also going on my trip who want to travel around after our program ends. Now they have planned to travel to Spain for a week, Poland for a day, Prague for a day, and Italy for a week (stopping in several cities). This is where I begin to get stressed. They plan on rooming some in hostiles and the rest "couch surfing". This seems scary to me. Yes, some people are background checked and have reviews, but these are random people opening up there homes to you to stay in for free. Sketchy? I also am completely uninterested in Spain and would rather see several other countries. Like Switzerland, Austria, Germany, France. I would love to see the other places these girls are going to explore however I am not sure if I want to spend the kind of money needed to see a place I am uninterested in. I've asked my boyfriend to come after my program and travel around Europe with me for a bit but we can't afford it. Pretty much I do not know anyone that can afford it. I need to buy my ticket now and may only get to see a few countries/ places while on this once in a lifetime opportunity. Help!