A custom cage can be hundreds of dollars or a cheap one can be found for under ten dollars. I typically recommend that you start with the inexpensive cages to figure out what you like. If this turns into a long term thing for you and your partner then you can look at spending more money. If you were new to skiing, I would suggest that you buy cheap skis at first to see if skiing is right for you and then buy more expensive skis when you decide to go professional.
How much does it cost?