There's a mass shortage right now unless you're willing to pay upto double/triple the price buying from resellers.
Problem is, the price is of antminers is increasing as demand outweighs supply.
Best option I think is to wait for bitmain.com and put order in early as possible.

These S9's will end up costing $15,000 in the near future,mark my words.
Then history repeats itself again,all those who invested get screwed as a new superior device appears.
How many time have we seen this already?
In the meantime, there's far too much to be made from this backlog and future pump of these current chips. Carry on

https://asic-antminer.com/
https://cryptohardwareshop.net
bitmainresell.com

Mate, i wouldn't touch any of these links posted above.
Some of those domains are only a few days old.
There are too many scammers out there taking advantage of people in a hurry.
Wait for bitmain, end of story.