Just another question to add to the mix here- I was curious about the contents of the standard 500mg disposable cartridges that are so common. How much BHO goes into each one? I was assuming about 1/2 gram but that's a wild guess
This might be old, but it shows that it varies wildly. At 70%, there would be 350mg per cartridge.
http://www.beyondthc.com/all-vape-pens-are-not-created-equal/