Here are just a few charts detailing the list and volume of merchandise going into Gaza from just the Israeli crossings.
It does not include what is coming in through Egyptian crossings, and it does not include what is coming in through the tunnels (such as the luxury cars and missiles).
It certainly doesn't include what they produce themselves with their own industries, fishing boats, farms and livestock.
It also doesn't include the water or electricity we (ie: Israel) still provide.
Click on the link to see the charts and pictures.