In 2002, my wife and I were in Munich and we took a day trip to Salzburg. We took a regional train to Salzburg, and while we were there, we saw everything I had wanted to see in Salzburg - Mirabell Palace (do-re-mi steps), visited the old town under the fortress and had lunch there. We went up the incline to the fortress, then walked around the hill to the cloister where Maria had actually been a novate. The cloister is closed to visitors, but we could go into the chapel. I was amazed that it didn't look like the one in SOM.
Essentially, we saw everything of interest in Salzburg, and it cost us almost nothing*, mostly the regional fare to Salzburg (actually we did it with a Bayern-Ticket which costs €42 for two people today).
I would not do a tour. It's easy to do on your own if you do a little research.
Radius is a little vague (probably intentionally) about details, but since they mention that it is a 2 hour train trip, I imagine the cost includes the round trip regional train between the Munich Hbf and the Salzburg HB.
Radius doesn't say anything about transportation in Salzburg. It is a 2 mile walk from the Salzburg station down Rainierstr. past Mirabell (which they do say they show you), along the "promenades along the banks of the river Salzach" to the old town, from which you can see the outsides of the Salzburger Dom and St. Peters church. It will cost you €5 to see the inside of the Dom and €2 to see the inside of St. Peter's. They say nothing about showing you Leopoldskron (none of it was actually in SOM, although the lakeside patio scenes were shot at a temporary set that resembled the actual patio at Leopoldskron.) Leopoldskron is more than a 2 mile walk from downtown. You could walk around to the back of the fortress hill to see the convent where Maria was supposedly a novate.
- Well, we did have to pay for admission and the incline ride up to Hohensalzburg Fortress. I doubt that that is included with the tour.