Originally Posted by
nebratu
I'm flying into Berlin, and looks like there is a T-Punkt store at the airport, might just pick one up there, unless it's a huge ripoff
I did this last November - the cost for the SIM and the included time (I forgot how much) was just under 15 Euros.
Like you plan to do, I used my unlocked U.S. T-Mobile Motorola V330 (quad), and my number was active before I left the store. If you need to refill, you can do so either on the "XTRA" website, or at any T-Punkt store. IIRC unused time is good for one year.