The actual hardware, especially the panels, have dropped so much in price that if you're capable and willing to do the work yourself you can have a solar install paid off in 2-5 years, depending on how much sun you get and how expensive your local power is. I've seen homebrew setups down south that were paid off in just over a year, but those were guys who live way out in the desert and were getting ripped off by their power company.
One thing you don't see anymore is fancy sun-tracking mounts. Back when panels were expensive they sometimes made sense, but these days it's pretty much always better to just install more panels instead. You can even point them differently, with half facing SE for morning sun and the other half facing SW for evening sun, flattening your production curve and allowing you to use a cheaper and smaller inverter.