Legally you personally can't buy a pound, I don't think you can legally purchase any amount at a dispensary either because you are out of state(not 100% sure on that). However if you have a MI card, you will be protected under the law and allowed to posess per the AMMA. You could do a Patient-to-Patient exchange, but the meds would have to be Free with nothing of value exchanged and that weight would legally max out at 2.5 oz.
Water cooler talk has led me to believe that dispensaries are willing to pay between $2,500 and $3,000 per pound for good quality, well trimmed medical grade cannabis.