Hi, I haven’t done too much reading on this topic so forgive me if im repeating a point thats already been made, but;
I think shop coins should be less scarce, you can sit and play for an entire day (low skill duelist (me)) and come away with 5, maybe 6 coins. Should people of my calibur really have to grind for 6 hours a day for 2 weeks before they can afford to buy Rare foil on one of their cards? I dont think so. Obviously for a high skill player, grinding away with a top deck they can drop people left and right and come away with 40-50 coins in a day, but cosmetics shouldnt be exclusive like that in my opinion.
Good place to start would be to give players ranked in bronze some coins too. Raising silver ranked coins from 1 to 3 and gold from 2 to 5 would be big improvements too!
Perhaps there could be weekly/daily/hourly tournaments for each ranking to enter (depending on how frequent is realistic) in which there are coin prizes for everybody, even those who finish last.
(Seems worth noting that im ranked at about 1400 at time of writing this.)
Another possible solution is to add like a daily challenge list, where if you complete the challenges set you get some shop coins, i.e;
Win 3 Ranked Matches (any division) Reward: 30 Coins
Activate a field spell 5 times. Reward: 10 coins.
Banish opponents monsters 5 times. Reward: 30 coins.
Those are just some ideas, take them or not i think it would be better to not have the cosmetics be this exclusive, 500 hour, high level player acquirable.