A barter system would be nice.

Select offer in coins tickets cards or cash. Ask for card coin cash or tickets. Your offers gets held up by the system and is released when it's cancelled/met or 24 hrs passes(or a selected time)

Trading with other players are often buggy with possible multiple account abuse yet bartering is safer.

Overtime it will become like a stock exchange. Some cards getting sold/bought at fixed amounts, card prices changing with meta shifts and famous youtuber deck builds.

It will definitely give more incentive to cash in the game too.