That largely depends on your location in Canada. Out in BC, you can get top quality for $120 an ounce. In the Prairies or southern ontario, you are looking at $240+/ounce for high grade in a lot of areas. If you live in the north, you are usually looking at $300+ an ounce.
So even at the cheap street price of $ 120 an once, that is $ 4.20 per gram. The price in Ontario you said on the street is $ 8.40 per gram. This is for street weed, it might be good, it might be shit. Plus, if you get caught with it, you can lose your house, your kids, etc. LP's will charge a fair price of $ 5 - $7 per gram on average, the quality will become better and standardized plus you are legal and not risking everything you have and own. The LP product will be tested, safe, delivered to your home, not some sketchy street corner. I don't see why anyone wouldn't buy from an LP. I certainly would never risk everything I have on buying illegal weed unless there was no other choice. I agree that everyone should be able to grow for themselves, but many can't, don't have the place, skills, time or ability to do so. Thankfully for them, there is the LP system. The LP system isn't great yet, but it will be.