Here's a question: How many have estimated the number of LPs they own and then actually counted them, using any reasonable method such as LPs per foot of shelf space? I see that in 2012, I wrote here that I owned ~2000. Later on in 2012, I mentioned that I had a friend with 7,000 LPs from whom I could borrow freely. Since then, and very sadly for me, my friend developed dementia and eventually died. When it became obvious to everyone that his LP collection (and CD collection and mountains of audio and video equipment) would never again be used by him, his wife gave me the keys to their house and told me to go there and take whatever LPs I wanted. (She had moved herself and him to assisted living, by that time.) Faced with such overwhelming abundance, I nevertheless took "only" 800 or 900 LPs, mostly jazz and blues LPs, a few in the classical genre. (She gave away the rest!!!) I had to purchase a new cabinet to store my new acquisitions, which forced me to take a rough count of what I had plus what I got from my buddy. I now estimate a total of 2500 LPs, which means I was over-estimating when I earlier stated that I owned 2000. It was probably more like 1500 to 1700 back then. The good thing about acquiring his LPs, besides the fact that I can silently thank him for the wonderful music contained on them, is that he was just as anal as I am; his LPs are in "like new" condition and don't require any maintenance on my part, like running them through my VPI record washer.
Someone wrote about yard sales and the like as a source for bulk purchase. I won't own an LP that is scratched or gouged on the playing surface, which is most of what you find at a yard sale or at Goodwill.