Why would trading cost more cards than usual?

lronA5

I don't get why burning cards for one card is necessary. This makes the trading system totally atrocious and removes the entire purpose of trading. This isn't trading at all to be honest.

TheJeffers

It has been deliberately sabotaged to the point of being prohibitively expensive and unusable.

This way, you will buy more packs as the only viable way to obtain cards.

It's a feature, not a bug or a mistake.