Yes, I was not speaking in terms of Etsy, but in terms of Stripe. For Etsy, yes, their cost does definitely increase as transaction cost gets larger, but only b

Yes, I was not speaking in terms of Etsy, but in terms of Stripe. For Etsy, yes, their cost does definitely increase as transaction cost gets larger, but only because the payment processor they are forced to use (there are no other options) charges a percentage of each transaction. It is on the payment processors side where there is no justification for taking a larger chunk simply because a number is larger. Risk management. Those money they are "processing" are not theirs --but the risk is, and the bigger the amount, the bigger the risk. I, for one, would never preside over a big monetary deal between two parties with the associated risk of getting sued/asked for the money, for some small fixed amount. Would you?