Train Travel from Vienna to Salzburg on June 4th

Go to the website of the company running the trains, ÖBB (Austrian Railways): http://www.oebb.at/en/

I did, and for 4th June it showed me 2 train departures per hour, prices mostly €19.90, but some up to €39 depending on which train you take:

There are also trains run by a competing company, Westbahn.
You can also buy tickets at: https://www.trainline.eu/ which sells tickets for both companies at the same prices as the company websites.
Tickets will come in the form of a PDF file attached to an e-mail, which you must print out and bring with you.

You can also just get on a Westbahn train, take a seat and pay the conductor when he comes around. They now have trains to Salzburg from the Hauptbahnhof plus other Vienna stations. Prices are very good, although maybe not as good as an OEBB Sparschiene ticket purchased far in advance, which is train specific and nonrefundable.
https://westbahn.at/en

Thank you both so much!
I was able to easily order tickets on the Westbahn site.

Rail Europe is an American distributor of European train tickets (for a surcharge). In former time this was a reasonable way to obtain those in advance. Nowadays, in the time of the Internet, there is no real need anymore for such a service. Booking tickets through the home page of the respective railway company is cheaper and more reliable.

Especially the Eurail Pass, which was introduced in the US by Rail Europe, is a rip-off, in my opinion.

No need to reserve seats going from Vienna to Salzburg. For that particular ride I take Westbahn and pay on board, saving my Pass day for a longer ride.

PM sent...

Berlin to Prague - 19.90 Euro
Salzburg to Munich - 16 Euro per person with a Bayern ticket
Vienna to Salzburg - 19 Euro on OeBB or 26.50 Euro on Westbahn (purchased on the train)

Total cost for all three train trips - 54.90 Euro per person

I'd be curious to know how much these tickets were on Rail Europe.

Salzburg to Munich - 16 Euro per person with a Bayern ticket

Prices for a BT are €25/1, €31/2 (valid all day for public transport in Munich). Alternatively: "Guten Tag Ticket", valid on the Meridian train only (local transport in Munich excluded): €23/1 €29/2.

I am assuming this is a couple.

We (my family of 4 adults) are also traveling from Vienna to Salzburg on June 4th. Which train do most of you suggest? We are staying at the Vienna Marriott and would like to leave from a station nearby. We will be returning to Vienna from Salzburg 3 days later. We would like a nice, comfortable train ride and are willing to pay a bit more for comfort if necessary! Thank you for any help!

Closest station is Wien Mitte, across the Stadtpark from the Vienna Marriott. You can reserve Westbahn Plus seats for about 20 EUR more per ticket than the standard 26.50 EUR ticket.
https://westbahn.at/en/

If you want to ride on the OEBB Railjet, it goes from the Hauptbahnhof about 1 1/4 mile south of the Marriott. You can get there on the S-Bahn from Wien Mitte. They have 1st class, and if you want to pull out all the stops, business class.

Normal class seats on both Railjet and Westbahn are very nice. Save your $$$ and spend it something worth it, like a nice meal. It is only a 2 hour and 20 minute train ride.

Thank you, Sam and Emily! Which would you recommend? I would like to purchase the tickets ahead of time online, and we would like to be able to sit together. We will have luggage as we'll be staying in Salzburg a few days. I don't think we'll need much flexibility for time of travel, so booking for a specific time would be fine with us. Thanks for your insight!

Although "Wien Mitte" station is closer to the Vienna Marriott hotel, I still would not walk with the luggage.

Right at the front entrance of the hotel there is a tram stop. Take the tram, go two stops, alight at the Opera, take the U1 subway (red line) to "Wien Hbf" (main train station).

From there you can either go by Westbahn or by OeBB (RailJet). I personally prefer the RailJet. There are trains to Salzburg every half an hour. For both companies you can book tickets online including a seat reservation (€3 for OeBB, €5 for Westbahn, per person). Try to get cheap bargain tickets, i.e. compare the prices for different departure times.

I'll leave that to Emily. She lives there. I will say that if you want a good price and can commit to advance purchase nonrefundable tickets, OEBB will be the best price. Seat reservations are extra in 2nd class for 3 EUR, I believe 1st class is included.

But if you want flexibility, Westbahn has a set price. You can even just board the train, find seats, and pay the conductor when he/she comes around. Westbahn seat reservations are 5 EUR per seat. You can board the train at Wien Mitte.

With OEBB you will have to connect with the S-Bahn from Wien Mitte to Haupbahnhof. You will arrive at the underground station and have to go up 2 levels to the Railjet platforms.

With OEBB you will have to connect with the S-Bahn from Wien Mitte to Haupbahnhof. You will arrive at the underground station and have to go up 2 levels to the Railjet platforms.

As I described before, from Marriott hotel the best way to go to Hauptbahnhof is via tram 2 and U1 (and not via Wien Mitte).

I have to disagree with wmt1. I would suggest walking 8-9 minutes from the Marriott through Stadtpark to Wien Mitte for the Westbahn train. I hate taking public transportation with luggage. Alternately, walk 2-3 minutes to the U3 Stubentor station and go one stop to Wien Mitte.

@Emily
I hate walking with luggage. Using a ULF tram (ultra-low floor) means no steps, i.e. you enter on curb level having not to lift your luggage.
I agree that there is a shortcut through Stadtpark from the Marriott to Wien Mitte, if you know how to find the lesser known south-end entrance of Wien Mitte, which leads from street level directly to the platforms.

Thanks so much for all of your help! I purchased tickets online for the Westbahn train leaving from Wein Mitte. I purchased the cheapest fare, but I did reserve seats so we are guaranteed to sit together. I will figure out how to get to the station once we are in Vienna. Thanks again!