Boiler swap were $15-20K bids minus $1.2K in incentives. A2W was $42.4K minus $7.5K in rebates (with some uncertainty as to rebate payout, because they could require additional weatherization as a condition of the heat pump rebate, which wouldn’t be known until after project commencement).
I think the difference is we have one company in that market and they can do 6-8 boiler swaps for the same amount of bidding and installation labor involved in one A2W job, plus that gets them 6-8 customers on maintenance plans instead of just 1. I have a sibling comment laying out some of the (genuinely) more work it would take to switch to a heat pump: https://news.ycombinator.com/item?id=34352854. It was going to be "2.5 to 3.5 days" for the plumbing crew, a half-day of electrical, 4 person-days of trade helpers (landscaping and rough framing), outsourced masonry labor for the coring, and multiple inspections. That's a lot of mouths for my job to feed for them to get just one customer (and around $10K in equipment markup to cover overhead).
I don't blame them for bidding it a lot higher than a job that takes just a plumber and an apprentice 2.5-4 hours with no outsourced labor and only one inspection in order to get one customer (and around $5K in equipment markup to cover overhead).