You could start by trying to do a by gold by post for crypto? I don't know if anyone's on that yet and it might be pretty easy to do with little investment if you find a reputable 24 karrot/.999 seller/minter...
It might be hard to work out what's legit and what isn't and will take time (you might also have to process impure versions if you choose I've heard of black and white gold at least....)
Crypto4Gold your just buying gold/silver ( not even pawn shop) ...you can even do it solo
There are 10 problems with Crypto4Gold :
1. Capital ... you need minimum 100k-150k to start
2. You need to find a trader that can exchange you fiat to crypto 24/7 at a good rate
3. You need a secret location where you can store the gold,silver / a good testing kit / and someone with experience to test the gold/silver and refine it
4. You need a location where people send you the gold,silver
5. You need a good shipping company if people don't agree to sell the gold to you ,so you can send the gold,silver back
6. You need a programmer / web designer / webmaster to take the orders etc ....
This problem solved as i can do it 7. You need a expert in commodities that can predict when to sell
8. You need a good team manager
9. You need someone that you can trust with the money and metals ( takes care of shipping / moving the metals / money )
10. You need someone with marketing / advertising skills
Alone i can't do it ... but if we partner up like 10-50 people it will be very easy ...