Don't ever delete that RAW file because you can come back and reprocess the image in future.
What is important is to TRASH those images that cannot make it. Trust me, we all got our share of less than perfect shots.
The discipline to take a hard look and decide that a shot isn't good enough and to delete it is a hard thing for some because shooting digitally often means shooting with wild abandon without thinking.
Increasing storage is a solution but without the discipline to delete, it's like throwing money to fill up hard disk full of images that are just so-so and not stellar. What's the point?