Bulbophyllum fletcherianum
Medium size division in a 2.5" pot available for sale at $50.
The longest leaf is around 15 cm in length.
Only 1 plant available. 
This Bulbophyllum species under section macrobulbon is quite uncommon and difficult to come by. Leaves of mature plants can be more than 1 meter in length. The plants usually carry around 30 dark purple flowers on each inflorescence, measuring around 20-25 cm in size.