If you have an Ace or True Value / Do it Best hardware store, they have one of the best seasonal displays of smokers, wood chunks, grills, accessories, etc, etc. Check them out.
Online, google "smoking wood chunks", and i got this:
of about 142,000
for smoking wood chunks
seconds). There's some reading for you!
Also, if you can keep an eye on craig's list, there is always wood in my area that you can pick up on the cheap...Earlier this year, I got this truck load of apple for free! That's the right price!