Software and IP cost viability for home use

You won't be able to use FPGAs above Cyclone V with the free edition of Quartus (Stratix, any 10 series except Max 10). You won't be able to use PCIe or anything else that uses transceivers either. You can use GigE, but only with an external PHY chip and does not use transceivers.

Some but not all higher end dev boards come with a device locked license for Quartus. This means you can use full featured Quartus (PCIe etc), but only for the exact model FGPA on your board. You can never upgrade to a newer version of Quartus without buying it. The license isn't transferable, so you can't get a used board.