ETL and UL both visit our jurisdiction on a regular basis. The cost is dependant on the amout of testing, number of peices, size of the equipment and of course, the amount of time needed to perform the testing. Last time ETL was in town was for a series of light fixtures (about 10) and I believe they charged $1500 (I'm not sure of the exact $$$, but I recall the number in that range). Best bet is to call and give them specifics so they can quote a price.