Fee paid at registration = Annual fee * Length of registration period + Storage deposit.
The storage fee corresponds to the amount of on-chain storage space required to store account information on the Nervos CKB chain, and DAS is carefully structured so that a fixed storage fee is pledged regardless of the number of parsed records stored in the DAS account. The pledged storage fee is 206 CKB per account. If an account expires and is not renewed, the storage deposit will be returned to the account's Owner address at the time of expiration.
Since DAS is a decentralized application running on Nervos CKB, it only recognizes CKB as a payment method for fees. Therefore, the DAS team maintains a CKB/USD price prediction machine service that allows the contract to know how much CKB should be charged when a user signs up, and allows users to pay in any currency due to the presence of a DAS registrar.