The most cost effective method is to get copies of the testing reports or the COC or GCC from the manufacurer or the importer of the product directly. This only costs you the time and effort of get their paperwork and making a new GCC out of it to reflect that the product has passed through your hands.
Otherwise then there is the having the supply tested by your business and the lab issue you the test reports. This method is neither cost or time effective unless you will be selling large quanities of the particular product. Lead testing starts at $60 per batch domestically, and many labs take the supply apart to test each composite part. So it's conceivable that if there are many parts to a supply that the testing fee will be $60 per sub-component. A poster in another thread reported that a test report they received on a snap broke the supply down to these individual components:
snap socket
snap stud
prong ring
Even though anyone of those parts is unusable on it's own (nor are snaps sold that way) that was the way the lab chose to test the supply.
So you would need enough supplies to first give over to the lab a decent sample size of the product to destructively test and then enough stock of the same batch/lot left to sell to recoup the lab costs.
If you would like to investigate different pricing from approved labs you can check @
http://www.cpsc.gov/cgi-bin/labsearch/ for the list of labs that do CPSIA testing. Once on the page you will need to narrow the choices down by selecting what country the lab is located in and what tests you need for your items.
