Memory is cheap. You said it yourself. To me, it's not worth deleting a single frame. If I take a shot that's not worth keeping, it gets deleted in camera before I transfer the files to computer. I'm just an enthusiast that takes the occasional photo shoot on the side for extra cash.
Even though most of my shots are personal pictures, I've got lots of 'em. I went digital in 2002 and have about 60,000 shots from 2002-2009, and another 40,000 shots from 2010-2012. To date, I've taken 100,509 photos in the past ten years. That's nothing compared to most full time pros, but even with over 100,000 shots, it only takes up a little over 600 gigabytes. It needs to be said that I shot only JPEG until 2010, and then only about half of the shots were taken in RAW. I take RAW shots exclusively now, which increases storage space exponentially. I've got all my photos backed up on four separate systems, two external drives, and online too. A also have backups on disc. I'm not taking the chance of losing a single photo.
Doing professional video is another thing I've done for over ten years. That's where the real storage space gets filled. On my main editing system, I've got nine terabytes of drive space, and I only have about 350Gb free right now. It's all filled with HD video. My external and network storage gives me several more terabytes. In comparison, my picture storage is trivial.
It's video where I'm forced to do what you are doing with photos. After many projects, I will delete the original clips and keep only the final edited video. During some projects, I'll produce several versions of a clip, applying different looks and effects. Those also get deleted after the project is completed, as they take up too much space.
I'm not a packrat at home, but I am obsessive about keeping my photos. They are organized and tagged so that I can find just the one I need, when I need it.
It's fun to sorta trip yourself out later realizing that you have an entire bookshelf full of hard drives.