That’s counter-intuitive, but it’s also correct. Normally, it takes (on average) 200 raids to get 50 bits for a badge, so you earn the gold for those 200 raids. With a double drop, it takes only 100 raids to get the same 50 bits, so using a double gold item gives you twice the gold for those 100 raids, or the same as the normal amount of gold you’d make from 200 raids.
Sounds like the latest iteration of the lack of clarity in gold costs while power crafting, as discussed in this thread. Basically, the game shows you how much gold you got from raiding before taking into account the cost of crafting each badge required for the badge(s) that you’re Power Crafting. Looking at your specific case: The 20M in gold is how much it cost to craft the badges above and beyond the 37M gold you earned from raiding, so those badges actually had a total cost of 57M. (Which brings up the issue of just how insanely expensive it’s getting to craft badges with each new rank, but that’s a different topic.)
Is each badge roughly 2M, or is it roughly 2M to craft all 6 badges one-by-one? If it’s the latter, that seems incredibly cheap. If it’s the former, I’m guessing you have a lot of the sub-badges already crafted. For example, if you have two Fa Family Shears in your inventory, you won’t have to pay to craft those for Dash’s first badge, but then you’ll have to pay to craft those for his second, third, fourth, and fifth badges. A difference of 2M is pretty big, but not out of the question.