I know many are against it, but I would say try it once to see how it goes. Also, ASK before doing so.
Coming from a Highschool with a similar situation as you hslighting, with
no budget for equipment/expendables other then what our two Drama clubs can get together, in order to ever get anything done I
purchase things a lot myself. And all I need to do is turn in the receipt to either a Drama director to have it come out of their account (note I said account, not budget, which they do not have either), or bring it to the business manager to come from the school's Activity's Budget.
Honestly, in a Highschool setting, putting a PO through can take weeks if not months which is unacceptable for things like tape. I can usually get a cash, sometimes check for larger ticket items, reimbursement within a day or two.
Again, ASK before you buy something, as they never have to refund you for something. Try it once and see how it goes, the worst that could happen is that you have an extra
roll of
gaff tape in your personal kit.
And in my case sometimes I don't even try to get a refund for tape because I use it for my own personal uses too, same with some more expensive things such as adapters, wires,
etc. I will often buy something specifically for use at the school but I'm just going to take it once I leave, being mine. Unless they want to buy it off me at that time. Example, we didn't have a single
Direct Box, so I went and bought one and use it at the school, but it is still mine whenever I want it.
Not telling you how to use your money, but I know as a student, it's the only way to get things done sometimes.
And like Edrick said, getting on the good side of your supplier is always a good thing. I know the people at ours pretty well and often get discounts.