1. Why is there such a large markup on coins over the raw metal? Should I expect that markup to be durable if I later sold the coins? Or is it generally better to avoid the coin mark up?
Because people are willing to pay it. No, you will only get something close to the spot price. Yes, run for your life from these "collectibles".
2. Why are Kangaroos cheaper than buffalos? Looking at apmex, 1 oz 0.9999 purity American buffalos are currently: $2075 While 1 oz 0.9999 purity Kangaroos are: $2005. The are both “reputable”, what accounts for this difference?
1. https://www.apmex.com/product/223496/2021-1-oz-gold-buffalo-bu
2. https://www.apmex.com/product/217664/2021-australia-1-oz-gold-kangaroo-bu
The difference is which format of collectible has the highest retail mark-up. It's a good business really. Buy 1oz of gold for today's spot price of $1908. Cast it into a collectible coin for maybe $10 per coin. Do marketing at $10 per coin. Sell to a goldbug for $2075.
3. Is it common to take physical delivery? Even if you trust the broker, the delivery process seems risky. Is delivery discreet and secure? Do people take additional steps to authenticate their purchase once received to verify that it is not counterfeit?
Not in the futures market it isn't, but deliveries still occur. Not sure - porch pirates are not part of my risk profile in index funds. You could weigh the coins or bars, but of course there's no guarantee somebody didn't put a couple sheets of lead and aluminum in the middle to get the weight right.
4. Does anyone have experience using fidelitrade as a metals broker: https://www.fidelitrade.com/products-prices/gold-products/. I think that this is the PM broker that fidelity investments (where I have my Roth) uses, which made me feel a bit more comfortable considering them (and they offer a vaulting service that I don’t think APMEX does). What are the most popular brokers and why do people prefer them?
Was it Warren Buffet or Benjamin Graham who advocated spending as little as possible on "financial helpers"? I can't remember, but if you can transport, insure, and pay rent on a vault for less than the 0.25% expense ratio of iShares Gold Trust (IAU), which can be bought through any broker, then that's where your fortune lies!
TL;DR: Just buy IAU instead of setting up a subscription with a metals broker.
5. What’s the general (speculative) landscape of the metals supply say 20 years from now, assuming Earth’s population grows but per capita demand stays fixed? Is solar power + AI going to give us low cost mining while the emerging space industry mines asteroids to send supply soaring or is it more likely that all of the easily accessible gold deposits get used up and supply goes down? Maybe the intermediate case is presently accessible deposits get used up, but we unlock new ones in the northern latitudes due to climate change so the production rate basically treads water.
There will be more people mining PMs, production will go up, demand will go up, and the overall PM market will probably be larger than it was in 2021. More mercury will be dumped in the Amazon river, people in Africa will continue to be exploited or enslaved to mine gold, and there's no telling what any of this means for prices. I think we're a long way from mining asteroids; a period of political stability in any one of a number of African countries would yield more supply than an asteroid. The biggest game changer would be an improved refining technique, which could send the price plummeting.
I think the speculative outlook for the USD is much more interesting. By all signs, we're a decade into a Japanese-syle disinflationary trap, where central banks struggle to keep inflation above 2% and asset bubbles come and go as demographic graying slows monetary velocity. In such a world, gains from one's PM allocation will come from opportunistic rebalancing, not PM's going to the moon.