A laptop cannot be upgraded easily aside from a hard drive and RAM. The only way you can upgrade 99% of the laptop GPU's out there is by upgrading the entire motherboard. This also goes for the CPU, there is usually a variance of 100 to 400 mhz you can change out on a CPU, but short of that you'd have to again upgrade the motherboard.
In short no, buy what you really need because upgrading anything other than a hard drive or RAM is almost impossible.