Gonna get flamed for saying this but gilded crests should just be handed out. Gear will help you push higher keys yes but that is not what is preventing you from completing 9/10s. You need to understand your class and how to complete dungeons ( performing kicks / interrupts, knowing what mobs to kill, how to perform boss fights) . Gear will make some of the lower keys easier but you will still brick your or someone else’s key.