Was it confirmed that BuyDig will not support the warranty on this phone? They do list on the auction and their website as it having a USA Warranty. I sent them a message inquiring how they handle warranty claims. Another option is to go the SquareTrade route, although I believe within the first year they require you to go through the manufacture.
Buydig had some reviews on their ebay page from people who bought a cell phone and buydig would not help them with warranty at all. On the actual ebay page they say "US warranty" although if you look up their warranty policy on their website you get this:
"We make no representation or warranty of any kind, whether expressed or implied, including, but not limited to, implied warranties of merchantability, non-infringement, or fitness for a particular purpose. All items purchased from our store are accompanied by a manufacturer warranty unless indicated otherwise. You acknowledge that any warranty in connection with all products or services offered on our site is solely provided by the manufacturer or supplier of that product or service
. For warranty information and/or assistance, please check the documentation supplied with the product or contact the manufacturer. "
And as I said - Blackberry does not deal with customers directly for warranty and will refer you back to the seller. Hence the concern.