I'm one of the developers of Alpha Polaris and I've tried to closely follow the english cd version release. It seems the release has been pushed back several times (the german version has been in stores since last year), but hopefully you will be able to buy it at the end of this month. The price range us developers set for the game is around 10-15€ and I've seen some pretty steep prices out there.
You can buy Alpha Polaris as a digital download from our website
for less than 10€ or for an additional fee order it as a cd, but it includes no retail packaging. If you buy from the website, all the money goes to the developer.
If you have any questions, I will do my best to answer them