That depends on the cost of your utilities which very by region and even company, for example you may have a for profit gas vendor, and a coop for electric or vice versa that would change those economics.

For me my electric rates are pretty high, and my gas rates are pretty lowso in the winter I doubt a heat pump would be cheaper, in the fall and early spring when you just need to raise maybe 10deg over outside sure, but in the deep of winter I doubt it