Shop to sell/trade unwanted characters?

I'd love for them to add a much more robust shard shop. Might sound like a broken record by now but I like the Hearthstone system. There you can break down a card into crafting component at a rate of 1/5 to 1/4 the cost of crafting a card of equal rarity. For example, say a card "rare" care costs 100 mats to craft, disenchanting a rare card gives you 20 mats. But hearthstone is much more generous with giving out packs so 1/4 is probably steep in this case.

The same could apply here but at say 1/2 scrap value rather than 1/4. Characters could be sorted into rarities based on where they can be farmed, and broken down into "neutral" shard shop currency. A GW farmable character is the most common, arena shipment and cantina battle farmable 2nd, cantina shipment and hard only farmable 3rd, and chrome only the most rare. So say Tier 1 common, Tier 4 chrome.

Avergage daily income of shards t1 15, t2 ~5-10, t3 ~2-5, t4 special so say equivalent value of 40:20:5:1 where a t1 is worth about 1/40 of a t4. I set the chrome value arbitrarily, at 5x a difficult farm but theres no real reason for it.

Get the scaling right and you allow fluid transfer of shards between characters at a premium. It's still way more efficient to farm proper shards but if you get a char you really don't want you can put it towards one you do. And then when a char is nerfed CG could temporarily set the scrap ratio for a char to 1:1 so you can siphon shards equally into a new char of the same rarity, allowing balancing without "lost investment" QQ.