Yep, it's 5K. Adjusted for rep bonuses, of course, so in practice it's more like 4-4.25k.
Yeah, I feel the same way about cold weather flying. It made sense when WotLK came out, but it's really just pointless now. Not to mention that, for some reason, it's more expensive than flying in the Kalimdor/Eastern Kingdoms is going to be.
I'm kind of surprised Blizz didn't reduce the cost of epic flying. They've been on a roll with knocking down riding skill prices lately. Now that epic flying doesn't offer as much of a boost as it used to (what with regular flyers giving you a 150% speed increase while flying and all) that seems like the next logical step.