Students do not have lots of cash. Professors do not either, especially at OU. The cheapest and most useful backup program I have used is Super Duper. This is not an ad either.
It was just $29 years ago, contunues to update for free and it has seemlessly taken our home Mac drive data through recovery from computer fails and equipment upgrades. The best feature is that the external backup drive it maintains is a bootable copy of your drive. So, you can immediatley boot from the backup drive on another Mac and keep working untill you get your busted computer fixed or replaced.
Read more details in my science blog