register-domaintransaction cost depends on the length of the domain you want to register. You can see all the transaction cost parameters in
<n>, you look at the field
register_domain_<n>. The price in token is then calculated by the formula
price = register_domain_<n> * 1000000 / fee_coin_price
fee_coin_pricewill be updated to reflect the market value of the IOV token. The intent is to keep the price of the domain registration stable vs a stable currency.