3D printed part

What material?

A local tech school I used to attend has an ABS printer.

I'm very interested in the materials cost, and how much business your school is allowed to conduct.

I've approached them about doing a batch of a sorely needed small part that I think would be super easy to do.

I don't know whether to offer them a percentage of the profit or to just offer to pay per piece plus a donation to the school.

Thanks.