He is literally giving them an offer with a smaller profit margin than he already has with his other trading partners( 2.5 mana stones per blade of grass - 1 mana stone for the seeds = 1.5 mana stones of proftit )... even though he already sells them at only a fraction of the market value which in turn causes the customers of his friend to cause trouble. What is even dumber is that the parents of his friend, who run their own business, don't even think about raising their prices when their product is instantly sold out and the demand is so high that the customers are disrupting their business. This is simply infuriating to me!

Why is he only selling it for that little? If the effects of his vismian grasses are thrice that of mana pills, which are sold for 5 mana stones each, one blade of grass should be worth at least 15 mana stones. Aditionally it's mana is easier to absorb. Even if he gives him a quantity discount he should at least demand 10 mana stones, making a total of 10,000 mana stones instead of just 2,000 or 2,500.