@2d6fed24 There is some encouraging progress from Octopus on bringing down prices https://octopus.energy/get-a-heat-pump/

My ASHP system didn't come close to the install cost you've outlined (for a 3 bed detached house replacing an oil-based system with no boiler). You can read about my experience at https://medium.com/energynotes/good-bye-oil-hello-air-source-2f8851c1cd0d

Happy to share actual costs privately 

 @66c8914f will have a read, and might come back to you thank you. Going to get some expert advice on what's feasible for us in a mid terrace house.