I think it can be confusing the way that wood is described. From what I read, a guitar made of sapele can properly be called mahogany, but it will look different from typical mahogany (as Guitar Pix showed us).
Here's some info about mahogany I found on a guitar website:
"Mahogany is a correct name for ANY hardwood belonging to the family Meliaceae.
"Sapele and common Mahoganies are of different genera but both (and many other woods) are of the mahogany Family: Meliaceae.
"Mahogany was first used in the New World for two species of the genus Swietenia, namely Swietenia mahagoni (West Indian Mahogany) from the Caribbean and Swietenia macrophylla (Honduras Mahogany) from Central and South America.
"One Mahogany is Sapele, Entandrophragma cylindricum, from South East Asia. It is a medium reddish-brown hardwood with a marked stripe figure.
"The Mahogany name is also used for species from the African genera Entandophragma, Guarea and Khaya, and the Asian genus Toona (Phillipine Mahogany and others).
"Here is a description from Albert Constantine Jr.'s "Know Your Woods" book, first published in 1959: SAPELE (Entandrophragma cylindricum)
This species is also known as Aboudikrou, Sapele Mahogany, Sipo, and Tiama. Sapele grows in Nigeria and along the African Ivory Coast. It is a large tree and logs often come as much as 72 in. in diameter, though the usual range in the market is 30 to 36 in. The color of the wood is a dark reddish-brown with a very strong stripe and at times the grain is very irregular. This irregularity causes the plum pudding and blister figures so highly prized in the veneer field.
"The wood is very fine in texture and care has to be taken in the seasoning as it warps badly. Sometimes it is mistaken for African mahogany and is used as such; HOWEVER , IT IS HARDER AND HEAVIER, weighing from 35 to 40 lbs. per cubic foot, AND THE STRIPE IS MUCH MORE PRONOUNCED. Sapele is superior to either African or American mahogany in strength and is somewhat similar to the strength of our American oak. Sapele is used for interior paneling and also in general furniture work."
One thing I learned is that Martin had been making the 00015 out of sapele a few years ago. Then they stopped making that model, and in 2011, started making it again, this time using only traditional mahogany. So, if the Craigs List guy is selling a 00015 and it's made out of sapele (which by the picture, it sure looks like it) than it can't be a 2011 model (at least according to the source I found--which may be wrong!).