As a Moroccan, The best option for you would be to go half board as quality food in quality restaurants can be expensive in agadir.
But you will find a few average restaurants which may be just ok. so you can eat once a day outside the hotel and taste the moroccan traditional food.

average prices:

breakfast: 20 dh (coffee and crosant)
Lunch: 80 dh
dinner: 100 dh including non alcoholic drinks
total: 200 dh = 15 british pounds

Alcohol is expensive in bars and night clubs. it can cost up to 80 dh for a beer (6 pounds)

hope this helps