Due to Scarce light sources, demand is high for consumable light sources.
Demand is exceeding the supply.
There is much money to be made for manufactures and purveyors of light sources.
The same goes for providers of the resources used to produce light sources.
There is a shortage of those resources.
I could also depict people scrambling to join the industry as the economy attempts to reach equilibrium and align supply with demand.
Due to some monsters being hindered by light, it is in their best interest to discourage the production of light sources.
It would be interesting to depict monsters vandalizing light production facilities.