Originally Posted by orangeology

diligence + luck + improvise + repeat

1. diligence
forum. ebay. vintage-friendly shops like Boulder Bicycle always have some interesting deals and continuous discovery of NOS stuffs outta no where. subscribe. Ben's Cycle is awesome, too. when search ebay, don't search with too much detailed info and exact word. think how a seller whose no idea on the value of the part would post a thing. ie.) shimano 600 ex tricolor crankset (i'm just making up) vs 'shimano crank'. you'd be surprised at the results. also do an intentional typo search like Campanolo. simano. gems are usually there with less competition hence lower tag. of course, you've gotta be on top of your game on what you are exactly looking for, and eyes and knowledges on the stuffs.

2. luck
can't explain this. some stuffs are meant to be yours.

3. improvise
unless you are doing a specific timeframe sales-catalogue level restoration (which is fun), improvise is fun too. prices on even a same item do fluctuate with no reason. if you realize what you hunt for is now on unusually high-side, either no rush or find an alternative still works, then see you can replace it later. found myself that, waiting for an item could well go like 3 years±. part of fun, too. i learnt a lot from improvise.

4. repeat
'til you find what you want at good price. trust me, it's still a way healthier addiction than watches or guns. i do another unhealthy things called golf clubs. you get the story.

by no means, lecturing you or anything. just sharing my experience here.