Items & Scrolls
You get items through chests and scrolls through missions. I classify them in 2 types, buff and speed up (aka gold) items. Buff items are those that will power up your heroes or guardian for just a few minutes. Speed up items are those gold items, like gold pouches, buckets, crates and piles.
Buff items are only good when you come across a 3-star boss. With these items it will become easier to defeat the boss. However if defeating the boss is pointless, like you don’t unlock a new hero with it, then I suggest not using any buff item on that particular boss. Just gather enough strength naturally to beat him. Any excess buff items should be sold at the Exotic Merchant. After all, permanent upgrades are better than temporarily buffs.
Speed up items can be good, often used for meteorites. They are also used to complete the daily quest, use 4 pouches or buckets (40-140 coins) to obtain 3 scrolls (240 coins). Resulting in a profit. They can also be used to obtain firestones more quickly, but it’s like a drug. Once you start using them, you have to keep using them to feel like you’re progressing further. Once you hit a prestige wall, like it takes 12 hours of normal gameplay to get a 2x multiplier on your firestones, you can start using gold items to lower it down. But this does nothing to push that wall further. Which means next run you have to use these items again, or else it’s going to take 16 hours to get a 2x multiplier. Overall I think it’s best not to rely on gold items, and just sell them at the Exotic Merchant. This gives you permanent upgrades, which will push that ‘wall’ further, allowing you to get 2x multiplier in shorter amount of time.
Speed up items are not affected by Midas Touch. However speed up items are affected by anything that increases your DPS. This is also why speed up items work very well on glass cannon builds. DPS counter does not take into account the survivability of the heroes, or even the state of heroes (dead or alive). All it means is their attack, and how fast they attack per second. So when you increase speed through a scroll, DPS goes up. Increase attack/damage, and DPS goes up.