As you mentioned in another comment the actual gas cost. That is higher than I was expecting. I can only hope there will be an option for mass fusing or some other way to try and bundle a bunch of actions all at once.
I could see people taking a loss after paying gas for buying, fusing, and trading. I doubt the average player is going to use an Excel sheet and work out if it’s worth or not. They will just do some quick math and think they could make a couple quick bucks for going through the process.
I’d hate to see gas be the contributing factor in not getting enough players to keep it interesting. I’ve played a couple of TCG where the player base was small and it gets boring fast facing the same dozen players over and over.