I looked it up on from that ebay seller, and it's actually just Musa nagesium spelled wrong. The seeds are really easy to sprout, so for cheaper you may want to give that a try. Another thing is if you sprout what is being sold as Musa cheesmanii, and Musa nagesium side by side there is absolutly no difference in appearence.
Musa cheesmanii grown in mostly shade in NW California-
And a shot from above(the big one)-