I am in southern NH and recently went to a cold weather heat pump system. We had an oil boiler before hand so I had all new duct work added in the basement with an air handler and 3 mini split heads in the rooms upstairs.

I got quotes for mitsubishi systems ranging from 31k to 39K. Ended up going with an LG Red system for 19k. I then installed an heat pump water heat myself so am now fully off of heating oil and it is great.

Yup, I got a quote for $30K for heat pump vs. $14K to convert oil to gas.

Also the rebate depends on also insulating your house.. which is a good idea in all cases, but not cheap either.