Rich Wizard, Poor Wizard

CREATE TABLE new_table as
SELECT id AS first_id  , deposit_amount AS `first`,
id + 1 AS second_id,
(
SELECT deposit_amount
FROM wizzard_deposits
WHERE id = second_id
) AS `second`
, (
SELECT ((SELECT deposit_amount
FROM wizzard_deposits
WHERE id = first_id) - (SELECT deposit_amount
FROM wizzard_deposits
WHERE id = second_id))
) AS diff
from wizzard_deposits
GROUP BY id
HAVING `second` IS NOT NULL;

SELECT sum(diff)
FROM new_table;