is there a OEBB vending machine or ticket counter in Munich Airport ?

No. Munich is in Germany, and the OeBB is the Austrian Railway.

As long it is a trip crossing the border between Germany and Austria, you should get at the German ticket counter the same tickets as from an OeBB counter.

Alternatively you can buy any OeBB ticket online. Their website is not the most user friendly, and your credit card must have enabled the European security features.

If you are going to Salzburg, that is the border station between German and Austrian Railways, so in that case you need a German ticket, which you can get from the DB machine or ticket counter.

I am going to Zelle am see, i want to buy Bayernkarte to salzburg from Munich airport and then Einfach raus from Salzburg to Zelle. I wanted to buy the Einfach Raus tickets from Munich airport. So wanted to know. Otherwise, i have to buy in salzburg.

The Einfach Raus ticket is valid for 2 or more passengers only. If you travel alone you will get in troubles. This ticket is valid for regional trains, only, the same applies to the Bayernkarte.

The route from Munich Airport to Zell am See does not touch Salzburg. You must change trains in Wörgl or Schwarzach-St. Veit.

The cheapest ticket I found online is € 14 (Sparschiene ticket) for the whole trip.

How many people traveling together? If one person, just buy a flexible ticket for 51.30 EUR using only regional trains. If two, you can buy a Bayern Ticket at the airport for 31 EUR out of the DB ticket machine. Go to Kufstein via Munich Ost. At Kufstein, you can buy an Einfach-Raus Ticket for two for 33 EUR. Then you will be traveling for 32 EUR per person.

If you go via Kufstein, you have a 38 train change there, time enough to buy the Einfach-Raus ticket out of the machine.

There is also a route through Salzburg, in which case its a 27 minute train change. Plenty of time to get the E-R ticket.

You can buy a "Einfach Raus" ticket (as wmt1 said, for 2-5 travellers only) from a Meridian vending machine at the Munich East station, where you transfer to the Meridian train to Salzburg. Just take an earlier S-Bahn from the airport so that you have time to find the (yellow / blue) Meridian automat.

The cheapest ticket I found online is € 14 (Sparschiene ticket) for the whole trip.

No combination of Bayernticket and Einfach Raus ticket can beat the Sparchiene price, assuming that you want to go just from Munich airport to Zell am See, i.e. no more train trips on the very same day. The Sparschiene ticket is bound to the trains selected when booking, but not restricted to slower regional trains.

The price for the Sparschiene ticket is tempting but if your plane is late the ticket will invalid. Nontheless with a price of €14 or €19 I'd be inclined to gamble. If you loose you can still use it for the S-Bahn ride to Munich East or Hbf and your loss will be neglegible.

So i landed in Munich at 5:40 am on 23rd September with my wife and daughter. I took a Bayern ticket from the airport for the family--valid from 12:01 am as it was a Saturday. 31 Euros. Weekdays, it is valid from 9 am.

I went from airport to Munich Ost. Then took a meridian train to Salzburg. Bought a Einfach Raus ticket at OEBB vending machine at Salzburg and reached Zelle by 12:44pm with beautiful weather. 37 euros.

Total 68 Euros for the entire family. There can be cheaper tickets as was mentioned by so many of you, this worked for my family and myself.

Thank you all for the help.

regards