In Dallas ISD, every single kid plays a school horn in every band hall unless they choose to buy their own. There are thousands of kids in the district in band. The district supplies 100% of the horns, because district leadership has committed to making sure that its schools have band programs at the middle school and high school level.
(Not saying it's paradise - it has all the other problems being a large urban ISD has - but every kid who wants one has a horn to play)
Dallas isn't the only one, either. There's a posting on TMEA right now for antoher program in DFW that has 100% school owned instruments for kids.
It can be done. You'll need a good chunk of change from your admin, but if your community is really unable to buy horns, you should start expanding your school-owned inventory bit by bit.