I can buy Antminer S9 13.5Th/s for 350USD. Is that a good price? I have heard that it is little bit noisy, so in my bedroom it is not the best place for it right?
Yes it is noisy but as long as you have free electricity any miner you buy you are in a win situation if you consider your initial investment as lost money. I would go personally for the S9 in this scenario and I wouldn't mind a bit of noise, in my bedroom I have a rig of six Gtx 1060 3 GB and they made some noise but they don't bother me, I sleep tight.