Mini Mining projet - starting next week

[ceasarpolar]

New to the community I am looking for guidance. I have been checking bitcoin's evolution for a while now and I finally decided to invest on a rig. I genuinely believe in its future potential.

If you guys can give me your insights I would gladly appreciate it.

I was lucky enough to find local suppliers for a reasonable price so no time wasted there, no preorder, I can start mining from next week. 

Rig
10 AntMiners S1 with PSU's ---> 3200$
10* 200GH/s=2000GH/s

1 ASIC Miner Dragon 28nm ---> 2000$
1TH/s

Total : 3TH/s
Total invested : 5200$ with all other charges 5400$.
I live in Canada, Ottawa, our electricity rate is 0.15$/kw including delivery and transmission.

Now when I plug all the information in the calculator it gives me ROI in about 90 days, starting from next week with difficulty increasing by 20% every month.

I decided to post this thread because I am freaking out now a bit, I am having second thoughts literally 3 days before meeting with suppliers and picking up items.

Also, I am not interested in buying bitcoins and holding, it s just boring, I prefer mining, I find it more interesting.
If you guys can let me know what you think with my phase 1 mini mining project I could walk with more confidence into this.

[Easy2Mine]

The error in your calculation is, difficulty don't increase 20% per month.
Difficulty increase every 2016 blocks, if 6 blocks are solved every hour than difficulty increase every 2 week.
But the reality is that more blocks are solved per hour, so difficulty increase every 11-12 days.

[ceasarpolar]

I still hit ROI in 90 days (before was 78 days with 20% monthly increase). I made calculations with 40% increase every month.
90 days ROI is still great!

[CoinToTheMax]

IF it is 90 days, than it is great offcorse