If you have the money, you should do it. It is about 60 euros if you do the round trip. But the view you'll get from that station is incredible. And the restaurant at the top isn't that expensive.
And if you are brave enough, you can go outside the station to walk a bit on the mountain :)
Allez consulter mon guide pour les meilleures choses gratuites à faire ainsi que des itinéraires et des conseils de voyage pour rendre votre voyage inoubliable.