These days, Graphic Cards can be divided into 2 big groups:
The integrated ones comes in the motherboard chipset (IE: G31/G33, 760G, etc.), the dedicated ones usually are add-in cards that goes into PCIe slots, and currently divided into 3 groups:
The low-end cards are cheap solutions that are better than any integrated video chip, usually from 30 - 80$ (IE: Nvidia GT520)
The mid-end cards are relatively cheap and can be used in a casual gaming machine, usually from 80 - 150$ (IE: Nvidia GTX 550ti)
The high-end cards are relatively expensive and are used in hardcore gaming / video hungry machines, they go from 150 to 1,500$ (ASUS Mars II)
So, low-end means: less video power, less components, less power consumption, but cheaper than mid and high end ones.
I have a GT 440 (512MB) that was 68$, i consider it a low-end card even though i runs all my games at max settings in 1360 x 768 resolution.
Based on its specs, it is a low end GPU, but i love it
someday i'll upgrade to a better system