Renting is the best way to get an instrument for your student for many reasons.
1.  You don't have to pay a lot of money up front.
2.  You are guaranteed to get a working instrument.
3.  If your student decides to not continue with band you can return the instrument with no penalty.
4.  It is a rent to own program.
5.  They offer maintenance and replacement coverage for very cheap.

The following video is not from this year so some prices may be a little different than what you see when you rent. 
The beginning of the video talks about the website.  Skip to 5:00 for the rental process.