Cheapest Way to Visit 3 Countries

[hockeyman1]

- I've decided that I want to visit: Germany, Denmark, and Norway.

- 2 week time span.

- I'm coming from the United States, so I'll need a flight to Europe.

How much would this trip cost (estimate), and how could I make this trip cheap as possible?

-Fly into Dublin and take a train to Berlin?
-Avoid Berlin, Oslo, and Copenhagen. Spend time in the smaller cities?
-Sleep on the train?

My goal is to keep spending under $2000 USD.

Thank you