I save most of the RAW image files of my photos, and with each RAW file being anywhere from 20-40mb I'd estimate the size of my hard drive to be anywhere from 40-80gb. I also duplicated the RAW files onto a second hard drive, but I have yet to move 98% of them into cloud storage.
Long story short, editing a RAW image file gives me much greater control versus editing a JPG or PNG, in which I can fine-tune the mids, shadows, colors, and more. I've periodically gone through and removed the RAW files that I know I'll never work with (i.e. blurry ones), but I ought to be doing it more often.