Here's a six hour duration tour of Aushwitz-Birkenau for only 118 zloty. Comes with an English speaking guide and it has hotel pickup in Krakow. That's about $43.
A direct flight from Stockholm to Krakow is going to be around $300 if you book it now. A ferry from Karlskrona to Gdynia will run you almost as much, then you woould have to take a train from Stockholm to Karlskrona and one from gdynia to Krakow.
Ill be going to Vienna in Sept for business/pleasure...anyone ever been...what are some things to do there..dont know to much about it..for the slow kids thats in Austria..lol