In order to determine how much solar panels will cost for your home, there are several things you have to look at. The first thing you have to look at is how much power your house consumes on average. Every home is going to consume a different amount of power. This affects the number of panels you will need for solar home heating (and solar water heating too, if you decide you want your entire home powered by solar energy).
The next thing to take into consideration is the location of your home. So many factors affect the efficiency of solar panels. These factors include the number of sunny days, rainfall, temperatures, how many hours of sun per day, how much shade you have in the area where your panels are to be installed, and even how windy it is (wind kicks up dirt and debris, which can decrease the panel's effectiveness).
To determine how much power your home consumes on average, you have to take into account things like the refrigerator, lights, computer, TV, stereo equipment, motors in fans and washers, hot water heating, and the household's basic heating needs.
The expense comes into play because solar panels aren't 100% efficient - in fact, they're significantly less! (at the time of writing, the highest efficiency achieved is 42.8%) This means you need more solar panels to power your home than you would if the efficiency were greater... plus, the more power you need, the more panels you need. If your panels are going to be located in an area where efficiency is further compromised by shade, wind, and other factors, then even more panels may be required to provide the energy you need. The cost can easily continue to add up. To make it a little more inexpensive, "handy" people might decide to build your own solar panel.
However, many people cut down on their energy consumption, in line with the whole objective of being eco-friendly. Plus once the initial investment is recouped through energy savings, you can continue to draw energy from the system for free.