OnDaq,
This one from Amazon seems like a pretty good deal.
https://www.amazon.com/VXB-Ceramic-Miniature-Bearing-8x22x7/dp/B01JKBUR1Q
It's a full ZrO2 bearing. There are two types of ceramic bearings (Si3N4 Silicon Nitride, and the ZrO2 Zirconium Oxide). Then you have full or hybrid. A full means that all components of the bearing are made from those elements. The hybrids will usually have the ceramic balls and the rings/races are made from some other material. Just make sure the size matches to the existing bearing in your spinner if you're buying a replacement online.
Regards, Nate
As far as the bearing goes, I've seen them from $10 (vxb via amazon) all the to the $100s. I personally haven't bought any full ceramic ones yet, but I'm waiting on some of the spinners I ordered to arrive so I might be looking to replace them if I'm not content with the ones that come in the unit.
Or $9.95 with free shipping on Amazon.
Can't say for sure without knowing what size/specs, it will vary by brand as well, but this one I picked at random on Amazon says it's 0.6 ounces most will be around this.
This is what I use (for the middle bearing): https://www.amazon.com/gp/product/B01JKBUR1Q/ref=oh_aui_detailpage_o09_s00?ie=UTF8&psc=1
(for the outside bearings) https://www.amazon.com/gp/product/B002BBD6X4/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
I timed my spin to 2mins 20 seconds. Not too bad
Well, they'll work, but they'll probably spin for 10 seconds max. If you're getting a 3d printer spinner, you can get those cheap bearings for the edge holes and then get 1 good center bearing. I'd go with this one. May be more than you wanted to pay but off brand bearings won't spin long at all