Bone stock Dell XPS 410 - upgrade graphics to Geforce 730 or 750?

What makes more sense to upgrade to? The XPS 410 is all stock as it came from the factory and currently sports a dying GeForce 8600 GS. I run 2 monitors and the DVI output is starting to get intermittent.  Flight sims and racing sims run okay but I can't run with everything on. I really don't play current games, mostly cruise the net and watch video.

The 730 are running around $70 and the 750 around $120. I know the MB and processor will bottleneck most of the newer cards of today so most upgrades are kind of a waste. I do plan on either upgrading a few things in the future or taking the video card with me to a new chassis when that day comes.

So, what would make the most sense? Saving a few $ on the 730 or getting a little more currently unuseable bang for almost twice the money? The XPS was a great decision, it has been rock solid for many many years, would just like to keep it going and get a little more fun with it.

Thoughts please?