All of the above, but I see that nobody has mentioned Craigslist. Like Ebay, you have to be patient and watch for a suitable offering. My problem is, that people offer up stuff that I didn't realize that I needed until just then.

But you can also recycle stuff back onto Craigslist. A few items I can think of that I scored from CL: ST2000+ autotiller, NIB (but 20 years old) powersurvivor 35 water maker, dinghies (bought and sold), dinghy motors (bought and sold), spare Atomic 4 engine (
someone had to rescue it) Old but never used storm sails that happen to fit my boat. New air conditioner/heat pump unit (some guy bought it for his truck, but couldn't figure out where the sea water pump would hook up to...) AmpAir wind generator that just needed a bit of TLC. Oh yeah, and the boat itself!
Caution: sometimes this stuff can be had for next to nothing or even actually nothing. But all the fixings and time required to install them can really add up in a hurry!
BTW: Speaking of consignment stores, last I heard, Columbia Marine Exchange in Portland was
still for sale. Your ticket to jump in to the marine industry and fix your boat on the side! Sadly, they were no longer accepting items on commission and were returning a lot of stuff to its owners (who *ahem* thought they had seen the last of it!) Getting liabilities off the books, I suppose. The owners have moved aboard their own boat and are heading out soon. It seems that this happens periodically - part of the normal life cycle of the store.
Anybody need a bunch of Lewmar #8 halyard winches with the old weird-sized handle socket?