There are liquid nitrogen places all over the country. You can go to Union Carbide. You can go to down to your local supply store. You can go to your high school physics lab. You can go to your local college, community college.
Liquid nitrogen is abundant and cheaply available.
It would float off the magnet that was placed below it and would hover until, of course, the liquid nitrogen evaporated, and the temperature rose, and the current suddenly was quenched because it was no longer was superconducting, and then the little ringlet of superconducting material would fall down to the lab bench or down to the magnet. The reason it would levitate is a property of superconductors called the Meisner Effect, or the Exclusion Effect, because what was happening is that the superconductor was basically shielding the inside from any magnetic field penetration from the outside. And the shielding produced a magnetic levitation. We're not talking anti-gravity now. We're talking just basic force balancing force.