Those god-damned oil furnaces are STILL legal in NYC?!

You may's well just get a barbecue oven, go collect as much plastic trash as you can find, and light it on fire in your house. You could pay off the mining hardware (mining revenues excluded) within a couple years if you switched from oil to electric mining. Mind successfully fucked, though.
It makes the most sense to buy moderate amounts of miners at the retail level if you live in a cold part of the world, as you can position the miners near windows and other cold parts of your house to serve as a replacement to your heating. This allows you to essentially have free electricity during the cold parts of the year.