Joe,

No need to buy expensive silly substrates. Think about the species you are buying and the normal habitat it would live in. I always recommend using Aspen or hemp for bedding / substrate. Aspen costs a bit more but both are very clean and don't smell at all!! They will also absorb spills and "bodily fluids" making it both easy and economical to clean.
Hope that helps? Oh yeah - DON'T EVER USE WOOD CHIPS!! THEY ARE EASILY SWALLOWED AND KILL REPTILES!!!! WE SEE TOO MANY OF THESE.