My 3000M NVidia died too and a fortunate eBay listing got me a direct replacement... very reasonable price and received within a week.
This is in a M6600 Dell Precision, which too has served me well with the only exception being the video drivers were dependent on Dell, not NVidia.
This is why I leaned away from Dell for my next purchase. I chose to go with a Lenovo P70 sinse it was certified with both Creo and SolidWorks.
A few notes: Choose the faster processors. Rumor has it the Xeon processor is -not- socketed! If you go Xeon, chose the faster one.
Also, go with the 4000 video card. The M3000M doesn't score too well in the happiness index. I also opted for the PCI-e drives. Add the second drive yourself; much cheaper for the commercial offering. Right now, Lenovo is having a very nice discount going. Wish I was shopping now.
But I could have looked harder at Dell. I completely missed the lower pages of compatible laptops where the Dell 7xxx are listed. Keep Dell in the running and see who gives you a better deal.
As to replacing your video card... it can be done. One thing about Dell, there is no shortage of documentation of how to get into the machine. Lenovo too has a fairly good maintenance guide. The machines are almost identical! ...the graphics cards in these machines use a standard buss connector easily inserted much like memory cards. You just have to carefully remove layers of stuff to get to it. Once you're there, you just transfer a few fragile and gooey heat transfer pads... reverse the disassembly order... and boot. Ebay abounds with replacement 4000M cards including new ones from China. I'd opt for a tested laptop pull, Dell Precision pull preferred.
Just remember that this is a hardware change. If you run some hardware licensed app, you might take precautions. SolidWorks, for instance, requires deactivating the license and reactivating it.
