Both of mine came from 6ave's steal of a deal, $2,550 on eBay. I bought one several months ago, and another a couple months ago, they came horribly packaged, but are resilient as ever and seemingly flawless. B&H and Adorama have always been my go-to's, but it was hard to pass up the eBay deal. I'll actually be purchasing another one next time the sale comes up and I would recommend that route to anyone.
If you can wait until, say, April of next year, do it. I imagine the 5Div will be announced by then at which time you can purchase the 5Diii from a more common dealer at a better price than offered today.
I hope this helps,