Amazon offers the AmazonBasics Microfiber Cleaning Cloth 24-Pack for $13.49. Checkout via Subscribe & Save to cut that to $11.47 and bag free shipping. That's 48 cents per cloth, $5 off list, and the lowest total price we could find. These 12x16" cloths purportedly absorb eight times their own weight.
Be sure to cancel your subscription once your order ships to avoid being billed for further shipments.