League of Legends (LoL) Question: First Strike Question

I have been trying First Strike Cho (because OP much?) and I am noticing the gold seems to be scaling incorrectly. Like should I have more gold than damage if it scales 100% plus the 5g on proc? I have been getting games that look like a non melee champ using the runes (like 927 dmg but only 758gold?) Just confused why the gold seems less than it should...