What type of xylophone would a middle school band use
would like to buy a used instrument for a teenager to practice at home
Try Pearl, or Yamaha. :) I think Pearl tends to be less expensive.
If you are asking about the brand, Pearl, Stagg, Yamaha, Musser and Adams are the most commonly used. Pearl is by far the most common because it has great sound and is relatively inexpensive. But, most middle school bands don't use a xylophone.