I don't remember how much it all cost exactly and I'm sure prices are different that a couple years ago. A few thousand for sure. I have a used inverter that basically fell into my lap for a good price, everything else is new. I built the panel racking out of what I already had and I already had a box for the components. Basically you need panels, charge controller, batteries, and inverter plus breakers, wire, panel racking, and some other stuff depending on what you want. Lightning arresters for example. The wire and connectors added up to more than I expected so if you can scroung around you might be able to save some money.  

 Depending on your needs, if you can run some or all of your stuff straight off of dc, you can save/eliminate your need for an inverter. Lights on dc are easy, and you can get fridges and freezers they run straight dc. 

 Ok, so it is a bit of an investment off the rip. Aluminum or copper wire? Thanks for the thoughtful response. 

 That way I think about off grid solar is that you are purchasing the power all at once in advance. That part might cost more today that what you can get on the grid but eventually it will pay off especially if the grid power prices go up. Another consideration is the sovereignty. When the grid power goes down it's very likely I'll still have power from my solar power system. Not to mention once you interact with a solar power system you start to value the electricity much more and will likely be more efficient in the way you use it. 

I use copper wire. I don't know about aluminum one way or another.