Do I need to buy any IP to support PCIe or GigE on the Cyclone V ST?

PCIe is a hardblock on FPGA side and GigE is on the HPS side. However both are on the silicon and you won't need anything aditional to buy.

Both PCIe hard Ip core and GigE doesn't are license-free.

In Cyclone V ST, you can implement the GIGE using Custom PHY or Native PHY. These PHYs will have GIGE presets for you to select to help auto populate the required configuration during instantiation. Note that this is just the PHY layer. You will still need to code your MAC logic.