I’ve sourced everything for my builds on here and eBay; if you’re not in a hurry and keep a project on the back burner, then eventually something you want will turn up cheap. That said, often the specific parts I need are only available in (eg) the US, and not cheap. As I’ve said, I don’t think I’ve lost money on mine over the years, but best to build just for yourself and avoid thinking about resale value.
One I forgot about (and still own) just to show bitsas don’t have to be Fenderesque - this was acquired as a nice bitsa P/J Fenderbird from a local BC-er, and gradually morphed into a “Mike Lull-type” custom Thunderbird with every component except body replaced:
Warmoth one-piece mahogany body with book-matched cocobolo top.
MIK Epiphone T’bird neck
1980’s Gibson logo Schaller M4S tuners (as on Victory bass)
Dual Thunderbucker ‘66 pickups imported from US (cost probably over twice everything else put together, but fabulous pickups.....)
Solid brass ‘60’s type bridge & tailpiece (also from US)