Hello sir,
I just read your project description and i am here to offer you my services. I would like to suggest that you can have an admin panel sort of thing for the farmer side where the can see how many buyers have visited their page where the crops are present, and they can have a check on how much crops have been sold and how much are left. Moreover,we can have a detailed discussion about the requirements once you conisder my propsal!
Regards,