> I'd struggle to get to 3,000.

I have that many books plus 500 CDs and 200 vinyl albums. My wife has a couple of hundred handbags and a similar number of coats and jackets.

But books are by far the largest class of thing in my house. I can't imagine having 300k items, even 30k seems rather unlikely in a house where you can see the floor!

Edit: I'm not in the US either so my house is probably smaller than the average US on though possibly larger than the other Brits commenting here; I'm in Norway.