That's a little costly, but I guess development of a board like that isn't cheap.
I note that it has a PCIe x8 slot, but they don't have drivers for a video card (or any card) yet so it's kinda useless.
SiFive demonstrates the HiFive Unmatched using a $300 150W Radeon RX580. https://www.youtube.com/watch?v=HVsnnYuvDXI
You can complain that you don't want to spend that much on a graphics card [1] but you can't complain that it's not supported.
[1] cheaper ones will work too