If you are looking for Tincs, I would be willing to throw in some Yellowback juvies. Shipping would be the only expense..
Part of what developed my affinity for nature was my high school science teacher. I am forever grateful for his hands on approach of getting us to experience the natural world that can be easily overlooked when surrounded by concrete and metal. Kudos to you for wanting to bring this special hobby in to the classroom!
Please do let me know if you are interested in some frogs and we can work in getting them shipped out to you.