I tend to agree about not purchasing instruments unless it is an absolute need. I would say that if you want to purchase some instruments that you would otherwise not purchase (for example specialty percussion), that would be appropriate.

Could you use this money for enrichment? Purchase a set of tuners, Smart Music subscriptions, books or music? Again, thinking about things that you would not otherwise be able to justify.

What about an additional trip to a concert? Lessons or masterclasses perhaps?