So lets see some math using Syonyk's input. I realized it is a 280w space heater light.
$0.127 I pay per kwhr electricity
213 watts used by current bulb in excess of LED bulb (280w -9.5w -9.5w -9.5w-18w , 3x60 watt bulbs + 1x100 watt bulb)
726 BTU generated per hour in excess of LED bulb
720 hours used in heating year (6 month x 30 day x 4 hour)
Cost to run light for remainder of heating year in excess of LED bulb = $21.40
Light generates 571,608 BTU's in excess of LED bulbs over course of heating year
That is 5.72 therms the furnace does not need to use. Assume the furnace is 80% efficient per Syonyk. I will additionally assume that the furnace as a heat source is only 60% as efficient as the light. The light is in the room we spend most of our time in, which also contains the thermostat and thus reduces heating. Plus the furnace has losses from stratification, escaping air, and it heats the entire house rather than the one room. The result is 11.9 therms, which means the furnace uses about twice as many therms as it needs to provide the same equivalent heat experience to us occupants. A Wild Ass Guess.
I pay $0.96/therm. $0.96/therm x 11.9 therms=
The furnace can provide the same heat as the incandescents for $11.44
The incandescents do it for $21.40 per above
The furnace and LED light bulbs will be $9.97 cheaper to run over the course of the next six months.
Even if I assume I will pay $30 dollars for LED bulbs and lose 3% interest on that over the course of six months, plus 3% depreciation of the $30 LED bulbs over six months, it looks like it will still be cheaper to switch to LED's.
The advantage to using LED lights and natural gas heat is $8.17 even after including 6% interest and depreciation.
Moral of the story: Natural gas and LED's seems to clearly beat incandescent bulbs by cost, per my calculations.
Darn, I was hoping it would tell me to take the easy way out :(