Delrin with a stainless bearing tip. Needed the slightest of balancing (I did some preliminary, but can be fine tuned depending on how picky you are). Just shy of 2.5" diameter and just over 100 grams. You could tighten the nut to make it play fixed, but the tip probably won't let go of the string for easy regens... though I didn't seem to have a problem with it releasing when I tried it.
For this one... let's say... $45 shipped (USA) cause of how pretty it is. I think I can ship it internationally for around $55, but I'll have to look at your specific location and shipping price.
How it looks spinning: