So back to my point that we haven’t seen the full impact yet. The OP says in 2018, taxes will raise the price from $35 to $55-$60. In 2018 we’ll see the black market boom as people want to keep their pot budget closer to the $35 dollar range. Basic law of supply and demand, particularly as high school and college students have limitations and habits. Basic market pressures in play here.
Here’s an article saying that the new taxes will be used to crack down on illegal pot growers in Colorado (i.e., the black market).
“A measure signed into law by Gov. John Hickenlooper sets aside nearly $6 million a year in Colorado marijuana tax revenue to reimburse police for investigating black-market marijuana activity that authorities say has increased since the state legalized recreational marijuana in 2012.”
https://www.usnews.com/news/business/articles/2017-06-08/colorado-marijuana-market-funds-busts-of-illegal-growers
The article indicates that the black market is hard to address because illegal growers wishing to market to out of state sales set up massive growing operations in rural areas that lack sufficient funds to police them. Those operations aren’t exactly going to dry up once the price jumps up.
On not in favor of legalization, but raising taxes, then using the tax money for enforcement, etc., just seems like they’re chasing their tails.