150 g would be reasonable. It does not take long to get whatsoever, and it's like paying for protection. If you were to get scammed in sure your rares cost more than 150g. Seeing there's a trade system I assume Stefan wants a fee so he can actually make money on the game. This was a great idea everyone had wanted it for so long, I'm sure people will buy packs more to get items to trade for rares now anyways, knowing they can't get scammed.