Kelsey,
My opinion is that you always want to keep the raw version of any images generated. You can always create a JPG from a raw file (NEF to JPG), but JPG is a lossy format meaning the conversion process does not allow you to go back to the original.
I know it might seem like a large amount of data to store, but I always think about the cost to regenerate the images and that is going to be way more expensive than the cost to store the images.
Even on a budget two hard drives (a primary and a backup) can be a reasonable backup.
I am not sure where you are based, but many universities also have some form of research space and you might be able to store data in campus cloud space.
Ryan
J Ryan Allen
Project Coordinator Southern Rocky Mountain TCN
Project Manager Biodiversity Informatics
University of Colorado Museum of Natural History
Herbarium (COLO)
350 UCB
Boulder, CO 80309
303-492-3216