We will be visiting Berchtesgaden for only part of a day. We are interested in seeing the Eagle's Nest, but we are unsure if we can see it without a tour. The english speaking tour is at 1:30 and we need to be leaving by then to get to Vienna. Any suggestions or recommendations?
You certainly don't need a tour to see Kehlsteinhaus (Eagles' Nest). I've done it twice without a tour. When I was there the first time, there were English speaking guides at the bus parking place just below the "Nest" offering guided tours for a few Euro, but if you've done your research, and are already familiar with it, even those tours are not necessary. The special bus fare to the top includes the elevator to the Haus, and you can just look around for yourselves.
From the Bushaltestelle in front of the Berchtesgaden Hauptbahnhof, its a 12 minute trip on bus 838, which runs about hourly, to the Dokumentation/Kehlstein Busabfahrt stop at the bottom of the mountain. There, at the kiosk, you buy your ticket for €15,50 to the parking place below the top of the mountain and the elevator to the top.