Does anyone know where we could stay affordably 21/9 - 23/9.....We are coming from Bamberg and would like to experience Octoberfest...PLEASE HELP

What do you consider affordable? You will probably do best to stay in a town a bit outside of Munich and train in.

Where woud be the best town to stay in?

I've stayed in Garmisch-P and day tripped in - tons of inexpensive (vis-a-vis Munich) guesthouses there but there are probably closer bases folks can recommend.

Coming from Bamberg making Augsburg - fine town about 45 mins from Munich - Octoberfest grounds are a short enough walk from the Munich train station (and a shorter walk from an S-Bahn station just before the Hauptbahnhof or main station.)

Contact the Munich tourist office. See if you can get a room in a private home. Cheap, and in the city so you can stay late in the tents.