This 1,400W bitcoin mining device provides essentially the identical energy efficiency of a 1,400W $30 space heater.

So if you would run a 1,400W space heater 24/7 for five months each winter, and would use this ASIC instead, your TCO over five years is ... impossible to calculate because there's no way to know the future bitcoin exchange rate and the future bitcoin difficulty.

But for the first year is (assuming today's price and difficulty):

TCO after one year:

Heatbit: $1,149, plus $69 shipping, minus $150 (revenue earned this winter), plus $150 for electricity for the winter, or $1,218.
Cheap space heater: $30, plus $150 for electricity for the winter, or $180.

Let's say in the second year this ASIC earns you $50.

Heatbit: $1,149, plus $69 shipping, minus $200 (revenue earned the two winters), plus $300 for electricity for two winters, or $1,318. Cheap space heater: $30, plus $300 for electricity for the two winters, or $330.

etc. for years three and on, where the difficulty increases and thus bitcoin revenue from this device decreases as a result.

And that assumes you truly run the device 24/7 for the five winter months. Space heaters are oftentimes used only to supplement heat in a living area (i.e., run much less often than 24/7).