Not quite a slam dunk.
This is the math I came up with.
138,500 btu per gallon of heating oil
570 gal used a year avg price of 2.59/gal = $1,473 per year
$1.87/100,000 BTU
78,945,000 BTU of oil to get 63,156,000 BTU of heat
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29.3kwh/100,000btu = 1kwh = .144 $/kwh x 29.3kwh = $4.22/100,000 BTU
ductless heat pump = 63,156,000BTU / 2.5(eff.) = 25,262,400
25,262,400 * $4.22/100,000BTU = $1,066 per year
At $407 per year savings thats an ROI of 15 years roughly.