Its a late reponse, but I'd thought I put my 2 cents in worth anyway
If your upgrade falls thru, a international triband (900/1800/1900) bought on ebay still might make sense. Even if you don't travel overseas alot, you may have friends and relatives that make the occasion trip and they can use the phone. I'm borrowing a 2nd phone from a friend for my father to use when we travel to Europe this summer. My friend went to Europe only once, but this will be the 4th or 5th trip for the phone
Plus you can always list it on ebay when you get back and recoup some of your costs.