If its truly 6 months old it still has 6 months of warranty. Make sure you get the original receipt or have your dealer call their repair center and check to see if the serial number was registered at purchase.
OK deal if it's clean. Warranty will most likely still be honored. Look at the first 4 digits of the serial numbers on the impact, batteries and charger. First two are the year, next two are the week of the year it was made.