What is the ruling on selling one type of frankincense at two different prices, while claiming there is a difference between them, and what are the implications of answering with "Good, God willing" when commenting on the quality of a product?

This action is impermissible as it involves two شرعي (religiously unlawful) prohibitions: The first is lying by making one type appear as two types. The second is deceiving the buyer by leading him to believe in the quality of the more expensive type. The statement "it is good, insha'Allah (God willing)" while knowing its lack of quality is a lie and a deception. Attaching the matter to the will of Allah in this context is of no benefit.