I'm constantly amazed by how much eBayers are paying for absolute tat - like near to £100 for awful Falcon/Peugeot/Raleigh racing bikes with chromed steel bars, 'safety levers' white plastic saddles, usually rediculous 25" frames....oh of course, adding the words 'fixie ?' in the title gets certain people excited.
Maybe I'm just still bitter that a couple of years ago, I sold a full 531 racer, 105 groupset, '92 Chorus chainset, singlespeed (new KMC chain & Shimano BMX sprocket/freewheel), Rolls Saddle, quill 3TTT stem and bars (in gloss black), all in mint condition, and got £140 for it.
Anyhow, I do think the decent 'retro' stuff is potentially a good investment for the future and I commend anyone who has stocked their garage up with old Campag/Italian/British/Californian/Japanese nice stuff - even if their wives disagree !