I guess buying an antminer S5+ could be a better option and plus as other users have already explained ,you cant even fell it if you buy just 1 miner ??
you make very less Roi's on single miners ..and so if you buy many miners ,those less profits gets multiplied ..so simple.
Problem is it is sold out on Bitmain's site. No one really knows if they will do another batch or if that was to get rid of last of chips.
This leaves dealing with ebay/forum or the worst resellers. Some of the prices on resellers are crazy. But if you can get for a decent price it is a very nice unit. Just make sure you have the electricity for it.