An additional process of tumbling the paver is required in the manufacturing process.  In the past pavers would be tumbled in a huge drum, similar to one you would see on a cement mixer truck.  The pavers are slowly turned and tumbled inside the drum and restacked on a pallet ready for delivery.  This process is time consuming and can add from $2.00 to $2.75 per square foot to the material costs once breakage loss is factored in.
A newer in-line tumbler has been added to many manufacturing plants recently.  The second cost factor involves installation.  A joint sand stabilizer must be used to protect the wider, irregular, tumbled joints.  This can be done with polymeric sand, which has polymer binding agents that harden the sand lock it into the joints.   Polymeric sand can add up to .80 cents per square foot to your project depending on the particular product selected.