Travel / Train costs Gdansk-Warzawa, Gdansk-Dresden, Warzawa-Czech Republic [4]

Hello forum members!

I'm from Mexico and I'll be in Gdansk for one week in a bussiness trip, and I'll have an extra week to travel around.

I have to go to Dresden, but I'd like to visit Warzawa and Czech Republic.

Do you have an aproximately price for this train tickets? and travel time between cities? if you have suggestion about a good tour inside Poland just tell me!

Wich is the cheapest way to move in Polan?

Regards

Benito A.