JOEL - Here are the scriptures in question:

17 Yea, and the herb, and the good things which come of the earth, whether for food or for raiment, or for houses, or for barns, or for orchards, or for gardens, or for vineyards;
18 Yea, all things which come of the earth, in the season thereof, are made for the benefit and the use of man, both to please the eye and to gladden the heart;
19 Yea, for food and for raiment, for taste and for smell, to strengthen the body and to enliven the soul. 20 And it pleaseth God that he hath given all these things unto man; for unto this end were they made to be used, with judgment, not to excess, neither by extortion.

Considering all these verses in context of this section, I really don't think selling marijuana is what God had in mind when He said this. These verses are talking in general terms about all the herbs and foods that come from the earth that should not be used in excess nor taken from anyone by force(extortion). It is lawful to obtain the good things of the earth by honest labor but it is not lawful to forcefully take them away from someone else.
Notice He said, "and the good things which come of the earth"(verse 17) are for the benefit and use of man. Even though God made marijuana, it would not be considered a good thing for the benefit of man; the same as for example some mushrooms that are poisonous, which God also made. This is how I interpret these scriptures.