In most cases, we're not all lucky when it comes to premium boxes. Truth to be told,15% Myth chance is not enough on gold boxes. You would mostly end up getting a new useless weapon or either the same myth over and over again.(who buys silver and mythical boxes anyways?)
If you're lucky, you would sometimes get a mythical and more lucky of you if you got a broken overpowered myth. But, what if you're able to refund you're mythical? Now of course a myth to another different myth would be extremely broken and abused system. What about if you we're able to refund you're (useless) myths to tokens?
How about like this:
Mythical Resistances Drainers Mark I: 10 tokens per each
Modules: /Mark I: 5 tokens each/Mark II: 7.5 tokens/Mark III: 10 tokens/Mark IV: 12 tokens/ Each Module
Drones: /Mark I: 5 tokens/Mark II: 10 tokens
Swords: 15 tokens
I don't know what to price the other items since they have their own use so maybe you could give the prices? I think that each item should be priced differently because they're different of uses and significance to each other. I would also like the price of tokens on an item be be increased a little bit when it's fused.