"Expensive" is always relative to the overall cost of construction. For a $400K home being custom made that's not as huge a hit as it would be to some place that's a $100K fixer-upper.
An in-floor heating system can easily cost $5K or more. Installation is the big cost on these things.
Expensive is already relative to the alternative. If a furnace can provide the same comfort at $5k, it takes a long time for the cost savings of the heat pump to make that up.
The real savings is that in new construction, you don't have to pay the extra cost to retrofit.
An in-floor heating system can easily cost $5K or more. Installation is the big cost on these things.