title: MySQL select SUM of results with a LIMIT
body: <p>I have a table full of items and prices for said items.  I would like to grab the SUM of the 3 highest priced items.</p>
  
  <p>I thought perhaps <code>SELECT SUM(items.price) FROM items ORDER BY items.price LIMIT 3</code> but that does not seem to do the trick.  Is this possible?  Thanks!</p>