I bought DELL PRECISION M6600 i7-2760QM 8GB 750GB, back in June of 2012 for $1,345.00 refurbished on ebay. I saved that way about $1000. Warranty for three years (from the time of when I purchased this machine). In case if anything happens, technician will come to your house and replace the part within 3 business days. If you are working with point clouds, I would recommend solid state HDD. I can give you seller id if you need it.
I bought a Dell M6500 through Dell last week, high-res 17" laptop with i7 quadcore, came out to $455. It's really insane how cheap the off lease equipment is sold. I just got it in and loaded civil3d on it and ordered 16GB or RAM for it. Money well spent on a machine that is a few years old.
I absolutely love it. It's my second Asus and both have been phenomenal. The one thing I did do to it is replace the HDD with an SSD, then put the HDD in a slot that replaces the DVD drive as a second drive. I then bought an external USB case for the DVD drive. It was already a screamer, now it's just flat out amazing.
I haven't upgraded the RAM, but that's probably the only thing left to do, if and when I feel like I need it. Right now, I don't see the point.
I could see where more RAM would be beneficial for high-end software and calculation needs. I don't really seem to need it.
