We were also on a rental program at our school. A set of stuff was rented for labwork for the whole year, and instruments & handpieces to treat patients were picked up and returned daily by the student.
But what happens when you lose the slow speed motor you rent from the school?
You pay the school whatever price they have assigned for slow speed motors. It happened to a lot of classmates. Popular expensive rental items to lose were slow speed motors ($500), angle adaptors (it was easy to throw this one out and not even realize it, then you go digging in the trash for it, $???), torque multipliers (so small yet so expensive, $100), Hanau torches ($100).
Lost rented instruments usually went for approx. $10 each. Plaster spatulas & green bowls were among the most popular lost rental instruments/items.
So pay the $70 - rental program or not - and save yourself some grief.