That's awesome you got that quest! Thanks for the heads-up about the price, I will make sure to have 2mil saved up before I accept it.
As for your question, I used it as an excuse not to study and instead made a crop profit comparison thread
. The winners were strawberry (turned into seeds) in spring, pineapple (turned into seeds) in summer, sweet potato (turned into seeds) in fall, and blue rose in winter.