From what I’ve read, panels are sometimes only a quarter of the price of a residential solar installation. In that case, if the panel cost twice the price for only 25% more power, it might be worth it.
For example utility scale solar can be less than 30% the cost of a residential solar installation, but also adds profit margins, interest rates and distribution costs to a residential customer.
In the later Ringworld books Larry Niven introduced solar 'panels' sprayed onto any surface and wirelessly broadcasting power. The DIY installation costs would now be almost zero.