I find a 20% discount is needed and have gone as high as 30%. To keep from having excess scrolls I have no T2 scrolls producing buildings (I have one for the velvet). My moonstone libraries produce all my scrolls for the most part and I really don't over produce. Perhaps I'm lucky in that I am in an area where the scrolls problem is not as intense, but local market conditions are what you have to adjust to, not universal ones.
I have the same three boosts. I'm not sure using scrolls to purchase KP is a good idea in the long run as it means you just keep paying more and more scrolls for the KP. If they then fix the problem your scrolls for KP could be very expensive.
I have 6 large steel buildings. I trade steel for silk and sometimes crystal and it helps when my discounted scrolls move slowly -- by slowly I mean 48 hours. Usually they take less than a day and they are gone at 100k scrolls for 75k silk or crystal.
But wait! The game says the goods are all equally in value on each tier! How can you say they are not?! Some players keep arguing we should all just go along with what the devs say and trade our scrolls at 1:1 with crystal/silk. Are you saying we should not but, instead, pay attention to the demand/supply ratios instead? Such a radical idea!
And the work around for selling scrolls is also a choice. And "not a necessity caused by a game design flaw" assumes their is a game design flaw in the overproduction of scrolls AND there was not one in the other work arounds the players adopted. I'm not convinced that any game design flaw is here since in all cases the players have found ways to successfully play the game as it is. Perhaps the only flaw in the game is the perception put forward by the devs that they can tell us players what to do -- by telling us what is "fair" and what is not.
To all: If you think the over production of scrolls is the problem it's not. The real problem is an unwillingness to adjust by learning another aspect of the game -- real open trading. Letting the devs tell you what your goods are worth is handicapping you and causing, I believe, a lot of players to keep on believing a 1 star trade for scrolls, or a 3 star trade to get crystal/silk for scrolls is "unfair" and therefore to avoid them. Ideally it would be nice if the game never fluctuated the value of the goods and they were, in fact, always in a perfect supply/demand ration of 1:1. But they are not and good game play, or at least effective game play, means adjusting and ignoring what the devs say about "fair" and "unfair," trades.
If you want to help "fix" the problem though, and you are, as I am, a scrolls boosted city, cut back on your production. If all scrolls producing cities did that the market would return to balance (roughly speaking) and their would be no scrolls surplus. But if you insist on believing that scrolls are worth the same as silk/crystal you would have to also say that you should therefore keep producing the same amount of scrolls and just trade them for the silk/crystal you need at a 1:1 ratio. That's the game design, but that's not a realistic assessment of the markets, and, as many have found out, going that route just produces an excess of scrolls you can't trade at a 1:1 ratio.
AJ