Is 18mths state prison reasonable for 1lb. of marijuana(poss. w/ intent) in the state of fla. with 1 prior?

That was the offer from the prosecution..with admitting to the charge..shudnt it b like a accetance of responsiblity law that cud help with the length of the sentenc..bcuz 18mths seem a bit extreme for a non violent weed charge is ther anything that wud help...