An interesting piece this is, thanks for taking the time to put it together.
I've never looked into palladium at all either and know almost nothing about it, over seeing the price movements as a part of tracking the PM sector. I thought about getting some a few years back when the price was around $550-600, but like you pointed out the premium was way high. I also didn't have the sense it would've been an easy thing to turn around and sell the way gold and silver are.
You're welcome. The re-sale-ability of both Platinum and Palladium is part of the reason why I hadn't looked at them before. But maybe the times are a changing and the premiums are coming down. It is encouraging to see some mints adding Palladium coins and bars to their product lines.