Hi,
You have a number of choices from Tegel to Potsdamer Platz or the Brandenburger Tor area. 1. Take a taxi for the entire distance, too pricey for me.
- Take the TXL bus from Berlin-Tegel to Berlin Hbf, then take U-Bahn 55 to Brandenburger Tor, or take the taxi from Hbf to Brandenburger Tor. I would probably do this, ie, the taxi from Hbf to the hotel. If you want to go to Potsdamer Platz from BT, take the S-Bahn #2.
I can't say anything exactly on the cab fare. I took the taxi twice to the Pension in Berlin-Charlottenburg to Savignyplatz, once from Hbf since I was running late getting there, and once from Berlin-Ostbahnhof. The price was 11 or 12 Euro before the tip, can't remember from which train station.
Where is the hotel exactly, closer to Brandenburger Tor or Potsdamer Platz? If it's closer to BT, then you can take any S-Bahn line from Hbf to Bahnhof Friedrichstrasse, another junction point.