You can ask on Freecycle.org. Or maybe there is a computer repair service in your area? My aunt fixes computers, and she keeps the junk ones for parts. I have a Mendelsons store in my area, and they have aisles of those fans, all kinds and sizes, just thrown in boxes, for $5 each. Good luck!
I have some 4 inch fans.They run off 110.No need for a transformer or anything.Just plug in and go.I have them in my incubator they work good.10 dollars a piece plus shipping if your interested Thanks Rodney