We will be in Europe this fall and wanted to know if we should buy our train tickets in advance. Our route is Budapest-Vienna-Salzburg and ending in Munich for Octoberfest. We have always bought our tickets in advance, but feel it might not be necessary. Thanks in advance.
The advantage of buying in advanced is that you may get a discount. If this is "necessary" for you, go for it. But it you don't need to if your only concern is guaranteeing a seat.
Those trains are operated by Austria and some of the tickets are available at www.oebb.at, but they don't have online sales for the first leg of the RailJet, starting in Budapest. I would buy tickets in the station or at a Budapest travel agency when you arrive. These trains don't require reservations, therefore they cannot sell out, even if crowded.
You can buy the OBB Railjet Budapest to Vienna leg at Hungarian State Railways --- You will receive a voucher number which you enter in a blue machine near the station door ( Keleti p.u. ) . The machine will print the ticket . Look here http://elvira.mav-start.hu/elvira.dll