I'm at work so don't have my Calibre stats in front of me, but I have about 1200 books in it, of which around 400 have been read. That includes two magazines I subscribe to digitally.
Since I've been e-reading since 2003, and many of my eBook reads are library borrowed, that's only a fraction of the e-books that have been on my e-devices. I've read over 800 books in the last 5 years in Goodreads.
I have done a few purges. There were a lot of freebies from my eReader.com days that got ditched.
I'd like to have them all on my iPad, but I haven't found an App that can handle a huge catalog without bogging down.