Any time an item is transferred (traded, sold, or purchased), there is a small network fee, called a “gas fee”, paid to help power the Matic Network, which is an Ethereum sidechain (i.e. the underlying technologies that Skyweaver uses). At Soft Launch, Horizon will launch on the Matic Network and will cover the gas fees for players on Matic.
When purchasing USDC, the purchase will be processed by an external payment service provider, and you will incur a transaction fee. This fee is charged by the payment service provider, and Horizon receives zero proceeds from this fee.