I've been guilty of this to some extent. Hard drives are relatively cheap, but I have no desire to fill the garage with them or have a dozen 42U racks worth of storage servers in my basement. I know that gives many geeks the biggest hard-on imaginable, but I'll pass.
I have a single tower server that has a capacity of 15 drives. Recently I decided that I will not buy any more hard drives or upgrade the capacity of the existing drives. One day last week I took a couple of hours and deleted 600GB worth of files, then 200GB the next two days. Now have it on my daily to-do checklist to delete 100GB per day until until I've either created enough free space to last a couple of years, or else until I run out of crap to throw away.