Hi EOZ, welcome to Talkbass. Double bass is a wonderful journey - and you are doing well to ask lots of questions!
You will notice that Europe and other parts of the world have different markets in double basses.
Have a look around this site:
http://www.basschat.co.uk
Several people (mostly from the UK) have used Thomann and other mailorder companies with varying degrees of success and report their experiences there. There are some decent basses to be had for around the 1000 euro mark. Thomann sells Strunal basses that are considered solid and reliable. However, as a previous poster said, keep in mind that a double bass needs a setup and that will cost a bit extra.