i need to buy a new graphic card for my laptop
Good luck with that, 450 is probably the best price you will get as they need to replace the entire motherboard as often times even if it does use a PCI-E connector in a laptop it is hardwired in and isnt actually a slot due to space constraints.
Actually hunter315, this laptop DOES have a removable card. And it suffers (from what i have gathered around other forums etc) that when they were made there was an issue with solder purity and also a heat issue while running in the machine. I have also been searching for a reasonable price to replace the one in my 9400. The best I have found yet is $249 US from an online parts source. The trouble is, they are all pulls from reclaimed/recycled laptops.
There is mention about people baking their cards in an oven to try and reflow the solder. I have also watched (to my horror) a youtube video of someone carelessly disassembling their laptop and holding a heat-gun to the card. I am hesitant to try either method as it seems to be a temporary solution at best.
If you know someone that does electronics repairs and has the CORRECT TOOLS for reballing a BGA chip, take it to them and have the solder replaced on the card you have. I used to know someone who worked in the Q/C and repair department at Celestica here in Canada, I may try to track him down