My son is starting dental school in the next few weeks and needs a new laptop. His current 6 year old does not meet the requirements of at least Core 2, Windows OS, 4GB ram, 80 GB hd. This weekend Sam's has an HP on sale that is an i5. It specs at 6GB ram, 640 GB hd, 15.6 screen, etc. It's regularly $799 but is $125 off thru the 4th which would make it $674. They also have another HP for $599. i3, 6gb ram, 640 GB hd, 15.6" screen. Specs look about the same except the i3 vs i5. My question is: Is the i5 worth the $75 difference? It will be used for school, he doesn't do online gaming or anything like that. Thanks for any info.