A 200 mounts achievement has been added to the 5.3 PTR. I take this as a clear signal to start working on mounts again. As of this writing I'm at 180 or so, so it shouldn't be too much of a stretch if I put some effort in.
Up to this point in the expansion I've been mostly ignoring the goldsink mounts, such as the Jeweled Panthers, engineering rockets, that 120k reforging mount, etc, because there was never any point in buying them now; I could just as easily buy/craft them later on, and in all likelihood for cheaper. But now we have a handy deadline. I'll start setting gold aside, and as long as nothing extraordinary appears on the Black Market before then [like Invincible or Mimiron's Head] I'll make the purchases after the patch drops.
For now though, there are I estimate around three thousand welfare mounts that I've yet to bother to grind from the Pandaria factions. Not to mention all the pre-Mists mount grinds that I abandoned when the expansion came out. Maybe I wont end up having to spend anything.