There are a LOT of factors involved in pricing and grading. Beginning with the buyers personal preferences which include smell, colour, moisture content, cure, consistency, visual appearance (crystals?), smokability (does it go out?), and the biggest one of all - STRAIN.
I would suggest reading High Times cover to cover for the next year or two, and always be humble when serving medical patients, we know what we want!
Good luck on your career!
Cheers! https://beta.chainbb.com