The pyrolytic graphite is very expensive but if you want to experiment a low-cost diamagnetic levitation can try to buy the normal pure graphite and work it as I do in this video. The diamagnetic effect is very good when graphite is pure like the one used in the experiment. Obviously you also need a base of powerful neodymium magnets.
I therefore thank www.Bangood.com for the excellent merchandise that has provided me.
here the links to the products
99.99% Pure Graphite Plate Sheet: http://bit.ly/2hvKttl
Stainless Steel Plate Sheet: http://bit.ly/2ipSBZk
Strong Block Cuboid Magnet Rare: http://bit.ly/2ipOQTP