Question about if this is Halal Income


I have a question I wanted to sell these Mystery Boxes that contain Pokemon trading cards in them for example I would sell them by auctioning them on eBay and the auction would start at 1$ and maybe end at 170$ the mystery box would have a topic like Charizard Card mystery box and it would be a random charizard card but it could be worth more or less what they paid. I thought it could be bad so I came up with the idea to allow returns within 14 days of you getting it is this okay?

@Mufti_Faraz_Adam didn’t tag