Do you keep toys "to grow into?"
I've purged tons of stuff (former nanny and foster parents, now parent to my own 1 year old). Most of the kids I worked with were much older, so a lot of what I have is geared towards older kids. I hate getting rid of things that I think might be a hit down the road. I developed quite a reputation as the "fun" nanny that always brought something cool - shadow catcher, spin art, fuse beads, bouncy ball making kit, pop up tents etc... Most of my nanny things are geared towards 4-12 year olds.
Her interests have changed so much that I never know what she'll be into. How do you know which items to hang onto? And my collection of stuff was gathered over time and with ridiculously awesome prices at garage sales and whatnot. So yes, I could replace these things but I don't think I'd ever be able to buy it for super low prices again (and it would drive me crazy to sell something for $10 then later re-buy it for $30!)