Here is a breakdown of the fees that you can expect when using the in-game Marketplace. Magic Eden has a required fee for sellers (0.5%) and buyers (1.5%). 

But, there will be a ‘conversion' tax on all transactions involving a player’s taxable balance, any Honey (HXD) which they have Harvested in-game. This tax will be 40% for all FTP players, but will match the withdrawal tax of a player’s VIP level for all Beemium players. Any tax-free balance (purchased HXD) will not be subject to any taxes.

Purchases will ALWAYS draw from a player’s tax-free balance first and then any taxable balance if necessary.