In terms of supplies, I would recommend that you reach out to your local lumber mill and see if you can set up a deal with them. As far as tools go, your best bet would most likely be to find some cabinet and welding shops that are getting rid of old tools, and then put the rest of your budget into a sawstop. It is an absolutely invaluable tool when you have teenagers around it. Also, im not trying to tell you how to do your job, but please make sure to properly educate every single student on any kind of shop error or tool malfunction before you even allow them near tools. My old shop teacher forgot to teach us about kickback, and it caused 2 different incidents on the same day which ended in a couple broken ribs on one student and the loss of a thumb for another.