Great differences in fish food, aquatic plant, fish prices

It appears that there is a very great difference in fish food prices all over India. Offline in Panaji, Goa, they are charging Rs 80 for a packet of fish food, while online, the same packet is being sold for Rs 20. Some plants are sold for Rs 100 each in Goa, while online and in Mumbai they are selling for Rs 20 – Rs 30 each at one store. In Mumbai in another store in the same locality, aquatic plants were being sold for Rs 130 per plant, indicating the extremely high profit margins.
The major advantage of growing aquatic plants, is that they do not require regular watering, unlike conventional plants, which will dry up if they are not watered properly unless they are succulents like aloe vera, cactus.