I requested a quote from SLEEP'S PLUMBING, I'm so glad I did....
A very friendly guy from Sleep's Plumbing came to the house looked at the drain (outside the kitchen sink gully trap) and quoted $165, using a tool, he told me it would be $345 if he had to use a water jet or a machine. It took him about ten minutes all up using a long tool. The blockage was caused by fat and oil from washing dishes in the kitchen sink.