I've been listening/collecting since my tweens. Back in the day, NYC/Brooklyn was a treasure trove of cutout LPs. Virtually every little store had a bin of them, and Woolworth's had many bins. It was very easy to buy great, obscure LPs for $1.99. Of course, new LPs were also cheaper, and there was never a need to buy at list price. There were no such things as used record bins, except maybe at a garage sale. In college, I was a DJ at the radio station, and accumulated many LPs either as promos or from an industry service that sold them to us very cheaply. After college, I worked in a record store, and could buy things at cost. And so the LPs accumulated.
In the '90's, I was feeling trapped by all I had accumulated, and sold the bulk of them off. But then I started accumulating CDs... In the past 10 years, I've also started buying used LPs, just for the fun of it. Dusty Groove is my main source, though I do also frequent local stores.