Build up the 2.6G or get the 2.8G?

Might be switching from PC to Mac and while not pretty, as a lower cost comparable alternative to purchasing and new desktop Mac, I was thinking about buying a Mini Mac and using my old monitor (it does have HDMI inputs) and wireless keyboard

I was interested in upgrading to the Fusion Drive and noticed that I have a few options:

1) Purchase the 2.6G model and upgrade to the Fusion drive - $899.00

2) Purchase the 2.8G model which comes standard with the Fusion Drive - $999.00

I'm not tech savvy, so what do the extra .2Gs get me? Is it work the extra $100?

Thanks!