Out of curiosity here the results of a web search concerning the market of solar panels in the Netherlands. Result: panels cost ca. 1 euro/peakwatt. Add an AC-DC converter to your panels so you can actually use the generated electricity, as well as sell excess electricity to the grid, and you have to pay € 6.950,- incl. BTW (VAT) for a 5000 Watt system, consisting of panels, converter and assembly materials, no battery storage. Mechanical mounting can be done by a skilled hobbyist, but the electrical work has to be done by a professional (549,- euro). All-in professional installation (mechanical + electrical): 1865,- euro.
For a 3000 Watt system the prices mentioned above change to: 4250,- / 349,- / 1229,- euro
For a 1500 Watt system the prices mentioned above change to: 2350,- / 289,- / 959,- euro
Powergarantee 90% after 10 years and 80% after 25 years.