title: Best way to store list of items and properties within another list of items
body: <p>I need to store a list of items entered by the user. These items can have several classifications associated with them, and those classifications can have their own properties. What would be the best way to store data in this manner?</p>
  
  <p>Just for an example I'll use cars. The user enters they have a Ford. Then the user specifies which Ford cars they have (could be Mustang, Focus, etc). Then enters the cost for that Mustang, Focus, or whatever. So we would end up with a list of Ford cars each with their own cost. </p>
  
  <p>Then the user will enter GM and start another list of the same type. 
  This is how I'm seeing the list:</p>
  
  <pre><code>Ford -&gt; Mustang -&gt; $30000
       -&gt; Focus -&gt; $20000
       -&gt; F150 -&gt; $40000
  
  GM -&gt; Camaro -&gt; $30000
     -&gt; Corvette -&gt; $50000
  </code></pre>
  
  <p>I thought about using nested arrays but that doesn't seem like an efficient way to handle this because it looks like I'd have to nest 3 arrays deep. If I do an array of objects I will have to duplicate the manufacturer for each car (using my example) and I only want the user to see one entry for each manufacturer. </p>