A bit of 'coffee table maths'...
NoteCost
Average cost of the Rig$9,113
Average cost of power (per year)$2,920
The past 182 day mean BTC value$44,795
Typical BTC pool return (per year)0.294234
Annual Mining return (based on the above value)$13,180
1st Year Costs(-)$12,033
1st Year P&L$1,148
This does not include any hidden costs (installation, maintenance, etc) which could very well eat up any 1st year P&L, and then some, but putting that aside, you'd have an apx 4.5% ROI in the first year. To get the same return on a simple purchase of BTC, the $ value of BTC would be just 4.5% higher than it is right now. Hell, it could be 4.5% higher next week, let alone in 12 months.
Just to be clear, I'm not against the very idea, but if you do go down this road, do so with your eyes wide open.