I think you're probably apt to get another 600 if you have to go the Lockline route with your phone, they probably have a bunch.

Last week, my T600 stopped working so I went to the Sprint Store (because there was no physical damage so it qualifies for the $10 plan (and it was actually under 1yr so it was free) and I guess they had no more T600s at the store because they gave me a T650. I had to buy a charger but I'm still very happy.