Cost effectiveness of fireplace with insert vs electric furnace
electricity, hands down.

electricity at $0.10 = $330 / cord. (using estimate from link)

your wood is $1,065 / cord. ( 128cuft/cord * (1/0.6) * $5 ). that's high btw...

the electricity is 100% efficient, inserts are roughly 50%. 
checkout http://extension2.missouri.edu/g5450 for more info and comparisons.