Does a cyclone certified mounting system incur additional costs?

Does a cyclone certified mounting system incur additional costs?

Yes but bearing in mind the cost of the overall system, the increase will be minimal. There can be mini tornadoes, even in Victoria, so it pays to opt for a cyclone certified mounting system.
Solar panels have a wind upload pressure rating. For example, a rating of 5400Pa is roughly equivalent to a wind speed of 345km/h. 
A cyclone certified mounting system definitely needs to be used in northern Australia along the coastline.