Wow 2 Pages, really you have to step back, they are 2 different cards with different games, the GS budget aware gamer, excellent bang for buck, while the GTX flagship gaming product, more future proof but more expensive, it really is a...
Your best bet is to buy another motherboard of fleabay, I've seen one go for around $170 and it looked like it had the GFX slot, and swap out the mobo's and add a real GFX card