Okay, I grant you that I wasn't thinking about the luck of the values, only the luck of getting extra scrolls in the chests. So you may be right after all. You've given me a new perspective.I have a lot of respect for you, Darielle. You play a smart game with well thought out strategy. I know you believe your strategy got you your building set but it really came down to luck. You said "it is very unlikely that you'll fail to get an 18 or 45 three times in a row" but that's not true. Every time chests are generated their value is assigned using RNG so you have exactly the same chance of getting or not getting an 18 or 45 each and every time.
Calculating the best chest strategy isn't simply a matter of choosing lowest cost per chest or best cost to flag ratio as evidenced by this elvenar player who's been trying to develop an accurate formula and no strategy is a guarantee; if it were then I should have had the same outcome for all 6 cities instead of the wildly varying results I did get.