The initial costs of heat pump systems can differ a lot, and for some very good reasons. The type of heat pump system, the size of the house, and where in the world you live can all make the prices swing widely. For air source heat pumps, you might pay anywhere from $4,000 to $8,000—that's your basic range. For ground source heat pumps, it gets a lot pricier, going anywhere from $10,000 to $25,000. And when you start factoring in the price of equipment, local labor (which can really vary), and the system's design complexity on top of that, you can see how some homeowners end up paying a lot more.