i tried doing some searching via google and came to the same conclusion. I would imagine that Dish would provide techs with something like this if the cost were minimal.The cost of the equipment to do such a test runs into the thousands of dollars so I'm afraid there is no "inxpensive" way to test unless you know some who already has the equipment.
If someone wants guarantees, replacing the cable seems to be the cheapest option.
rdinkel's experience is a good sign that most RG6 cable will work as long as the condition has held up over the years. I would imagine many installers will start reusing existing cable once they figure this out as well. It will be a difference between what Dish wants and what works in the field.