I lived in an all-female dorm my first year in college. I was in Germany as an exchange student when they sent the letter about choosing dorms, and my dad picked the all girl's dorm.
We could have guys over to visit, but not after certain hours, like 10:00 IIRC. However, I went to a public college (Moorhead State University in MN). At certain private institutions, esepcially Christian colleges, the rules are probably stricter.
Also we only had twin beds, but you could get a loft or a bunk bed if you chose to.
As for cost, I don't remember exactly, but I think it was around $200-$300. It's probably gone up. I was in college in the late 90's.