Train travel Berlin to Prague
 

Travelling by train from Berlin to Prague - Monday September 9th.
Then train from Prague to Vienna
should I reserve now or wait until I'm in Europe?

Talk to the great people at Rick Steves now before you go.
You will pay no more and you may pay less. http://www.ricksteves.com/rail/
Did you ever watch him on PBS?

You'd do better to go read seat61.com, and post this question on the Europe board. You'll probably pay less booking ahead, so do that if you're sure of your dates, but not through Rail Europe.

Yes, book as early as you can for discounted fares (If indeed there is anything left for that date, it's getting late now), and you can use www.bahn.com - also for Prague - Vienna.

Lavandula

Pre-book at www.bahn.de/en, and Berlin to Prague start at €29. On the day, full-price is more like €55.

Pre-book Prague to Vienna at www.cd.cz/eshop and Prague to Vienna starts at €19.