The system was worth more than $10k (it was the largest allowed by law), but a good chunk of the cost was definitely the installation and 20 years full warranty. Luckily I was able to transfer that to the new owner. I have been specifically told that essentially all improvements you can do to a home won’t reflect the their cost in the sell value for the most part. You’re lucky to get 25% in most cases, solar is actually better than most things because it is fairly universally desired. Some things do better than other regionally, e.g. in ground pools can get most of their value in FL apparently as long as you don’t go overboard on costs.