Hopefully this will ease the burden of your conundrum,
For the sake of your current hardware vs. your prospective hardware in relation to upgrading before Inqusition's release here is the following:
1- Your current CPU is fine, as is for the purpose of playing this game between min. / recommended settings
2- I am going to presume that your system RAM memory is alright (min. 2gb / recommended 4 gb)
With this in mind, you have 2 reasons for focusing only on the GPU:
1- Getting the dedicated VRAM of 2Gb dedicated will make sure that your system does not have to allocate regular RAM to run all processes (being both game and regular PC operation), thus allowing for much smoother game play mechanics and look with little to no issues
2- you are saving a bit of money to at least get the hardware that will serve more of a purpose for the intent of playing the game..
and Recommended is a standard term for playing the game at the med to high settings using native resolutions and refresh rates; if you wish to try ultra high settings then yes you would want to aim well above those states to ensure that you would not see clipping (of screen edges), pauses in screen action, or a loss of fidelity in either imaging or game play, especially with HD or even new 4k standards.
Hope this helps! Enjoy @ Gustave