Hi Racsen,
My advice would be: if you want to play double bass, then get one somehow! As other people have said, renting may be a great option, especially as the resale value of a cheap Chinese double bass is not so good.
But I think that the real question you need to answer is, do you REALLY want to play Double Bass? After that, the answer to your question should be clear.
As far as Chinese basses go, I play a VERY cheap Chinese bass myself, and the main problem is the set-up. So, no matter what you do, make sure you get it set-up right. A luthier's or your DOUBLE BASS teacher's advice is invaluable in this regard.
By the way, welcome to TB, don't worry your English (which is fine by the way). It's great to see TB getting more international all the time.
