Based on your specifications, your PC could sell for around Php 20,000 to Php 25,000. However, the actual selling price may vary depending on the condition of your PC, the demand for it, and the location where you will sell it.
It's also worth noting that the Pentium Gold G5400 and GTX 745 video card are considered entry-level components. If you're planning to upgrade your PC, you may want to consider investing in a more powerful CPU and a better graphics card to improve its performance and increase its resale value.