I got some ipe (Brazilian walnut) flooring scraps at a building materials recycling place. It was just a couple of $$ for a couple of scraps that were 12-18" and thick enough to split on a band saw. Dense enough to sink in water, seems to polish up nicely. It is also commercially grown in some places.
I've also found some nice birdsyeye maple, oak, and walnut flooring.
Ric