Buying from manufacturer is safest, if you choose the right one of course 
I would tend to agree, and define the "right one" at the present time as KNC https://www.kncminer.com/?resellerid=233
It's not vaporware, they have a functional product at a reasonable price, and seem like a good chance of ROI. Everything else is by comparison a larger risk due to shipping dates likely to slip by months.
Used deals can be had, but eBay you're likely to pay too much, here you can get a deal but also get scammed, so it's a case of waiting for the right price from the right seller.
