Shredded wood chips are available FOR FREE if you know what you are doing! Here are a few I know about:
1)
Lindsey's Tree Service
http://northtexasvegetablegardeners.com/forum/index.php?topic=488.02)
Arborlogical Services Inc
http://www.arborilogical.com/note from Alice on facebook:
"If you want some free mulch, give them a call at 972-442-1524 and make arrangements to go pick some up at the shop in Wylie. They also deliver to areas nearby for a reasonable price."
Please reply to this thread if you know of more.