SSD is an odd case, it is the simplest yet most impacting improvement to a computer.

Graphic card needs fast buses, if your mainboard gets behind you won't have access to the latest. I remember struggling with this long ago (pci -> agp; pcie 2x -> 4x).

It may be less an issue nowadays, so my point was off.

ps: It's funny you consider 2011 vintage, my most recent computer being from 2009 and I find it modern :)