Yes...It's truly thousands...and that's after ridding myself of 1,000 or so books a few years back...Of my collection, probably 2,000 or so are first editions in "as new" condition signed by the authors. My insurance company makes me carry a special rider.
I collect hockey cards. I had forgotten about the ones I collected in the late 1960s and early 1970s until my nephew pointed out that people were paying a lot of money for them. About 4 years ago I sold selected cards for enough to put a nice down payment on a 1973 Ferrari [okay, Fiat] Dino GTS.
If they do find a cure for packrattery, I refuse to be cured.
Collecting firsts is not pack-ratting.
In one biennial book purge, I bit the bullet and sold about 100 firsts: Kerouac, T. Wolfe, T. Leary, Aldous Huxley, etc. A 60's/70's theme with some odd ducks like the mint first Brit edition of Seven Pillars Of Wisdom by T.E. Lawrence (found in a used book barn, paid maybe $20.00).
It was heartwrenching, but sometimes these purges must spare nothing.
Packratters can't even let go of a coffee can full of used pencils or an 8-track cassette player.
He came in and retired one morning with no warning and everyone at work wondered if he had simply wandered off to die.
Did you have them appraised to ascertain their value? I have a collection (though much smaller than yours), and my insurance company demanded proof of their value before allowing me to insure them. I've yet to do it because of the time, expense and overall inconvenience of it all.