WA and CO are where my experience was. The product is more often than not cheaper than the black market prices were.
It was pretty common for a black market eighth to cost 40-80 dollars, and you're looking at 20-60 dollars for legal stuff now even with taxes. It's a bit more expensive in WA but I'd say comparable to black market prices.
That's not even to mention the convenience aspect. You can buy a joint that will last a moderate user all evening for like 5 dollars. No need to roll it yourself and all that.