If you are here to flame/spam just leave because you will be reported. If you are here to say "oh get this computer over this one" without any proof as to why it is better then leave. I want serious advice from veteran computer builders/users.

I am up at Uni and the programs I am running (solid edge st5, autocadd, and autodesk inventor) need quite a lot of ram and a better processor than an i3.
I looked up how much it would be for an i7 processor and it would just be worth it to buy a new laptop considering the new processor would run me up to $400. I am hoping to get up to 500 for my current laptop when I sell it(2010, 6gb ram, i3, 17.3 inch dell).

I plan on getting an i7 and at least 16gbs of ram. What company do you guys suggest buying the laptop from? My roommate has a Lenovo and he says its great. I don't want to go dell, hp, or asus.

Also if anyone has any suggestions on how much I should sell my current laptop for, I would greatly appreciate it.
I would prefer to get a smaller laptop. 16 inch diagonal max.

Current Laptop: 2010 Dell Inspiron N7010 with 6gb ram, i3, 17.3 inch, M 370 @ 2.40 GHz, 64 bit operating system with Windows 7 Home premium and it doesn't have a video card.
Depending on how much I can get for the laptop I can spend up to $1200 or $1500 on the laptop.

I will be staying with Windows 7, don't try and talk me into Mac. For those who say go linux, first find me 3D modeling software that will work on it and then second I am holding off on linux until winter break. I will be getting Debian on my old desktop tower.