Any reasons not to buy AntMiner S9?

According to nicehash.com, an AntMiner S9 will give me a profit of $418 per month. Sound too good to be true?

I feel like I read everywhere that small scale mining is not profitable...?

Electricity cost is $0.08 kWh where I live, and my ventilation system can make use of the heat generated about 6 months a year.

QUESTIONS:

1. Why should I not buy an AntMiner S9?

2. In the $1500-$4000 range, are there better alternative that are not too advanced to configure?

3. Why are (used?) Antminer S9 on sale on Ebay? I read it's not available until next month?

Submitted October 01, 2017 at 11:50PM by GeeZuZz http://bit.ly/2xSmjQG