If you've seen the T3 in a store I'm guessing you're in Canada. Buy the T3 from BestBuy. It's on sale right now for $80 & $100 without and with the snap cover. It's not much more than the basic Kindle and if you like the Sony, go for it.
As others have said, you don't have to choose one or the other. Do both. Some books are just not in eformat yet so you can't get it. The Harry Potter books are an excellent example for me. I'm a bit of a dork so I'll happily reread them when the mood strikes and the fact that I can carry all 7 volumes in a device that weighs less than book one is something I relish.
They're small, lightweight and something I carry with me pretty much everywhere I go. I say treat yourself. You won't regret it.
