Your calculation is very useful. Thank you so much for that. I’m very bad at math, so I can only use logic instead.
Still, I think this is all still a theoretical case, like that worry about creating Mythic ingot from all Common ones would take a few million souls. Actual gameplay might be very difference that perfect situation might not always possible. Drop rate of each Treasure Tiers will play a big role here.
My prediction is that time will also have an important part. Waiting for perfect Treasures to drop might slow progress down. Players might have to sacrifice more gold to progress faster with the Treasure they have. Doing 100% quailty upgrade batch 10 times might be the best realistic way, and there are quiet many combinations possible; 20×5, 50×2, 50+30+20, 30x2 + 20x2, 30x3 + 5x2, 25x3 + 10x2 + 5, etc…