How much does LEV testing cost?

The number of systems you have, their complexity, and your location all affect the price. Large industrial sites with several systems could cost much more than a basic single-point extraction, which might just cost a few thousand rand.
The quality of the inspection is more important than the cost. A cheap test that omits necessary metrics is a false saving because, should the system fail, you could be legally exposed and your employees could be in danger.