£10k was the maximum given to those on benefits under the green home grant, without them having to fund any themselves. As such all heat pumps immediately cost £10k (some higher), and they were air to water because all photos I saw involved a new water tank which they needed to find space for inside the property. One firm were building insulated sheds to put them in, basically just wood and kingspan, if you had no room. The rest just looked like a giant AC unit, some of the photos looked like people had lost half their very small gardens on houses I suspect will see no benefit (even detriment) from the installation.
If they really wanted to make a difference offer solar, most people use much more electricity than gas anyway. It is still often made from fossil fuels so will help reduce our consumption, plus it will reduce the reliance in what we buy in from abroad whilst lessening the load on the grid. For 5k you aren't far off a battery system too.
