I've acquired a number of items via Craigslist that are near impossible to find and a few were Mac related (Apple stuff is probably 20% of my collection). I acquired a fully boxed Mac 128k, my Mac 512k with early Hyperdrive and at least one Apple Lisa 2. On a similar note, I got my TAM through a regional online ad that I found through a Google search. It resulted in a free Apple IIGS that was loaded as a throw in. Those all have conquest threads here.
If you actively look, you can find almost anything. I also found some items that the Computer History Museum would probably like to have. A working IMSAI PCS-80/30, an IMSAI 8048 (only 350 made and I'm too chicken to plug in), a couple of MOS KIM-1s, my IMSAI 8080, a Processor Technology Sol 20 with Helios II drive (mega rare). I've also missed a few items due to those who wouldn't ship or the item already sold like a FREE Commodore SuperPET (missed that one by a couple of hours), a MITS Altair 8800 (already sold) and the list can go on. Most of this stuff doesn't mean much here.
What I am still trying to find? An Apple Lisa 1, an MCM/70 (Canadian computer), a Bell and Howell Apple II Plus at a reasonable price.
What am I working on acquiring? A Pixar Image Computer in working condition with the SGI IRIS 3130 host computer but this was not on Craigslist. It doesn't look like it's going to happen because the seller is dragging his feet but it's not a definite no. It took me almost 11 months to land an IBM 5100. Forgot to mention that. It was also on Craigslist.