I would stay away from MDG. They have been known for one of the worst customer service reputations out there.
Dell computers are relatively cheap. I had a Lattitude 600 for work and found it very flimsy. I now have an HP Compaq laptop that's heavy yet sturdy. All computers from IBM are now Lenovo, a Chinese company.
As with any name brand computer, you do limit yourself in the future for upgrades and such. For example, my old IBM Aptiva I'm using is maxed out of RAM at a whopping 256 MB. I can't do a DVD burner, nor can I switch to some USB 2.0 devices without taking out a modem or network card. Still, it gets the job done on my end.
If you are looking for something that gets you onto CEG, emails, and watching the occassional mpg or dvd feature, you can probably have a system built out of generic and/or name-brand components for the $500 mark. I'm sure the classified sections have used computers, as well as local computer shops that buy out leased computers.
