Bikes I love buying the most are frankenstiens.
Basically at one point someone really loved that enough to give it so many goodies like:
10x groupsets
double walled presta wheelsets
extra set double walled presta wheelsets in their bags
aftermarket $$$ cantilevers
aftermarket $$$ indexed thumb shifters
brooks saddles
new condition Schwalbes (thank you very much)
They often come from apathetic sellers that don't own the bike.
But that surely isn't my fault when I tell them I'm available now and pay them the $50 advertised.
And if they say it's been reserved for someone else, I often bribe the seller with another $10-20 to ignore the other buyer. That one sounds illegal, but I assure you it is not and I'm ok steamrolling over slowpokes all the time.
Early bird gets the worm.