amendment 20 sez no such thing. amendment 20 is now 0-4-287 - ARTICLE XVIII Section 14 of the Colorado Constitution. We need to remember this fucker passed and is supreme. I'm pretty sure this is the only mention in the Amendment:

(d) Notwithstanding the foregoing provisions, no person, including a patient or primary care-giver, shall be entitled to the protection of this section for his or her acquisition, possession, manufacture, production, use, sale, distribution, dispensing, or transportation of marijuana for any use other than medical use.

so, with this mention, it is interpreted that all of the above ARE allowed for medical use.. there is really no difference between a patient and the caregiver as far as sales go, according to the Constitution.

Of course we are legislating changes to the Constitution now, so anything goes (away) I guess.