Ok, I am able to pick up one particular "exotic" wood, the botanical name is "Eusideroxylon zwageri" or common name "BELIAN". They grow exclusively in the Borneo Island. They're one of the hardest and most durable wood in the world, hence they're called "ironwood". To prevent it from extinction, the governments of Borneo Island have stopped exporting and only allow limited local usage.
Their mechanical properties are impressive (extremely heavy!!!):
Air-Dry Density: 835- 1,185 kg/m3
Shrinkage radial: 2.0 %
tangential: 4.5%
(I think the density of maple wood is typically 620-750 kg/m3)
Here's an example of how it looks, this little chair weighs 75kg (167lb!!)
Now, I am able to ask a local carpenter to build me a 4-shelves rack, each shelf is 2" thick and 17"x24", all for around US$400 (including shipping to the US!)
Should I go for it??
best regards
barry