I'm getting a return tickets to and from Prague because that is much cheaper than multi-city fares.
I intend to visit Prague, Vienna, Budapest, Krakow, Berlin. Travel in December 2016.
Need your advice here.

1. How many days for each city?
2. Prague->Vienna->Budapest->Krakow->Berlin and back to Prague
The sequence is correct?

Thanks.

Prague to Vienna from €19 ($25?) one-way, www.cd.cz/eshop

Vienna-Budapest from €19 one-way www.oebb.at

Budapest-Krakow try www.mavcsoport.hu

Krakow-Berlin book Krakow-Warsaw from €20 www.intercity.pl and Warsaw-Berlin from €29 www.bahn.de/en

Booking opens 60 days before departure.

How many days do you have for travel?

What are your interests?

Those are all wonderful cities. It's hard for me even to say which is my favorite, because there's so much to see and do in each of them.

Your sequence may depend on where you can get the best prices on air fares. Why not fly into one city, such as Berlin and out of the last one, Budapest?

YOur circle itinerary makes sense if you have to return from Prague. Are you sure that fare is a lot cheaper than if you flew into Prague and out of Berlin? Where are you coming from that this would be true? From where I live, those two fares would be about the same, and it would save you a lot of time and a train fare, and probably another vacation day and hotel cost, unless you get a flight home late in the day. That train from Berlin to Prague takes 4:30 hours and then you have to get to the airport, etc.

It really depends how much time you have, but in general, I think you'd want about 3 days in each city, not including when a lot of the day is spent in train travel (like from Budapest to Krakow, that train trip will take 10 hours at least).

You could go from Prague to Budapest to Vienna, then Krakow as there is a train that only takes 5:20 from Vienna to Krakow. You can get a direct train from PRague to Budapest in about 7 hrs (or 4 to Vienna). ALl told, it's about the same train time just how much you want to do in one day.

Krakow is really the most out of the way place, unfortunately, no easy way to get there from Prague or Berlin or Vienna or Budapest.

If i fly into Berlin, and out from Krakow, does it make sense?

Good gosh, what do you mean by "make sense"? Financially? Sequentially? Temporally? If you're American, flying home from Krakow means you're going to have a transfer somewhere because the only direct flights to the US are to Chicago (I think). Berlin has more options to and from the US even though it's not a major hub.

And how much time are you traveling? December 2016, like every other December, has 31 days. Are you using all of them?

If you're trying to do this trip in two weeks, don't. Cut it in half. It'll be cold and the main sights will be on winter hours so you have less time to tour about.

Prague - 3 days ( Castle almost 1 full day , Charles bridge, Old town square , 2nd Day - river cruise, TV Tower observation deck, Petrina Hill Tower and other misc things )

1 day trip to Cesky Krumlow

if you rush it, you can finish everything in 3 days including day trip. You still get 1 full evening if you return early from Cesky . Since the bus tour is 3 hours one way, you can catch some sleep on the bus if you leave early say 7 am ( reach 10 am ) and take a return bus at 3 pm ( reach at 6 pm ). And then spend few hours in the Old Town, but knowing it will be cold, you can decide how you would like to go about.