What to put on christmas list

I am ready to build my first pc, and the first set of parts just came in. I have heard that buying a discrete card improves video performance and frees up the cpu to do work tasks only. I will be using the i5 3570k with gigabyte z77x-d3h motherboard. I was wondering which graphics card or gpu chipset is most cost effective so that it can go up high on my wishlist of computer peripherals and components. Christmas is just around the corner.

I will not be doing any high end gaming, just civ 4, and a few really old games that I used to love. I will be doing Google Sketchup(3d cad freeware) around 10-25 min/day on average, so not that much.