The Bloodfang Widow was Legion's 'goldsink' mount, costing 2 million gold (which was about 1.8 million more gold than I had at the start of Legion, and 1.6 million more than I have right now).
Is there any chance Battle For Azeroth will have a similar high-cost mount for the rich players out there? Something in the order of 10-20 million gold? What could it be? The widow was great and there haven't been any other spider mounts, so a similar mount would have to be similarly unique.