The price of weed varies depending on where you buy it. The cheapest cannabis prices are found in dispensaries. A 1g pre-roll can cost as little as $5, or as much as $30.
In general, the price of weed is higher in states that have legalized recreational use and lower in states that have only legalized medical use. For example, a 1g pre-roll can cost $5-$10 in California but it can cost up to $30 in Maine because Maine has only legalized medical marijuana use.