The set would no doubt still be hard to find, but I think the set would go for a lot less if Rapunzel weren't part of it honestly. The reason being, because Rapunzel is so rare, when someone manages to get their hands on just her, they probably think "If I can get Rapunzel, the rarest one BY FAR, the rest are going to be much easier to get" and thus many people who manage to get Rapunzel try to get all the other ones because they already have the hardest one.
So in the end, I think if Rapunzel weren't in the set, they would be much easier to get and probably cheaper, but not MUCH cheaper. Remember that the Rapunzel R/C being so rare is what makes the set so talked about in the first place. Without the Rapunzel pin, the set wouldn't get nearly as much attention and thus wouldn't be nearly as popular, though still popular.