Price goes up, Demand goes up

When the price of a hedhi bileh goes up, the price of buying areca nuts and a Piper betle to put it on goes up.  We expect that the demand for hedhi bileh will fall soon, which is the answer given above. 

With substitutes, we may buy more on imported stuff like SUPARI and here is the opposite situation.  Most people might think of SUPARI and KILLI as substitutes, so when the price of areca nuts rises, people switch away from HEDHI  BILEH and start buying more supari or killi. but will this help?

So at any given price, people are willing to buy a higher quantity of KILLI and SUPARI, so the demand for these shifts right when the price of areca nuts goes up.

Can't WE STOP.