To the best of my knowledge, the rarest figured tree that was historically documented was "The Tree". It was discovered in the jungle of Honduras (now Belize) circa 1965. It was reportedly to be about 100 foot tall, 10' diameter at the base, had a spiral bark. However, when it was felled it fell into a ravine and they run into diffuclty extracting it. It wasn't till circa 1981 that an American Importer named Novak came back to that region to successfully extract the wood, chainsawn on site, dragged, trucked and a loader was used to push it along the Chiquibul river and milled with the use of an ancient power sawmill. About 12,000 board feet (another source states 13,000 bd. ft.) came from this rare tree- reportedly about a quarter had a "tortoiseshell pattern" with veining (and bait) and the rest had a quilted pattern ranging from sausage, blister, wavy figuring- about 5 to 6 patterns.
The couple of timbers I had the fortunate of handling had the toroishell pattern and the other had a rolling blister pattern. It is a really dense genuine mahogany (swietenia macrophylla) hardwood with the small sample in hand it was roughly 3 pounds, 8 ounces per board foot. It had a deep caramelized orange-brown heartwood when finished and the figuring on and color was kind of "holographic" to the best I can describe it. It had this "inner glow" when light hits it and a "water color effect" when you move the board to and fro. Most luthier that had the fortunate of using it has commented that it had fundamental tone closer to rosewood than genuine mahogany! Probably the most expensive per board foot that I know off. I read somewhere that mid range cost is about $ 1500 per bd. ft. and there are reportedly several conference size slabs that had asking price of five figures!
Full disclosure, photo's are not mine and from the web......