Upload & Sell: On
Adorama had the same kit with the 600EX RT added for $3,899 - $200 more - on eBay all of last weekend.
That is a USA body, Canon warranty, shipped with a regular Adorama receipt.
Figure the value of the 600 EX at about $550 if you need it, maybe $530 if you would sell it. (It is currently $569 at B&H.)
So that is basically $550-$200=$350 cheaper than the B&H sale. Plus, there was another $77 in "eBay Bucks" - to buy something with on eBay in January. So net-net is $350+$77=$427 cheaper. Almost a free 600EX.
If you have an immediate want/need/use for the camera, buy the B&H. If you only have a few shoots, wait to save a bit. Your call.
I was going to wait until March, because I don't work much during the winter. But I have a shoot Saturday and Sunday that I could use the 5D3 for. The net price was pretty good, so I bought one.
Cheers! Good luck.