There is no definitive answer to this question as it depends on a variety of factors, including the size, weight, and destination of the package. However, on average, USPS is generally cheaper than UPS. If you are shipping a small package, or if the item is light enough to be shipped via USPS, then the cost difference may not be significant. However, if you are shipping a large or heavy package, or if the destination is far away, then the cost difference may be significant.
Additionally, if you are shipping multiple packages, then the cost difference may become even more significant. Ultimately, the best way to determine whether it is cheaper to send books by USPS or UPS is to compare the cost of each option and calculate the difference.
