Are there savings or promotions to be had for bulk purchases of Wuthering Waves Lunite on Manabuy?

https://www.scribd.com/document/987617415/Wuwa-Top-Up-Fees-What-to-Expect-When-Recharging-Lunite-in-Wuthering-Waves-125187

Are there discounts or promotions attainable for bulk purchases of Wuthering Waves Lunite on Manabuy?