I have some driftwood that I bought a long time ago. I'm fairly sure that the small pieces are Mopani wood although the person that sold it to me said it was Malaysian
Anyways, they are relatively small pieces so they are great for nano tanks. They float but if you soak them in water for a month or so they sink.
I also have three Malaysian driftwoods (last two photos) and three lava rocks that I never used (third photo).
All three lava rocks (third picture) - $5
Set 1 driftwood (8 pieces, first two pictures below) - $15
Set 2 driftwood (13 pieces, fourth picture) - $25
All three Malaysian driftwood (last two pictures) - $15, or $6 each
For now, this will be pick up only in Pembroke Pines or Miami, FL. But if you are really interested in the smaller Mopani driftwood sets, I will look into shipping for you.