... stupid answer: Whatever somebody is willing to pay ... What is the condition? A full bike or just a frame? I have several new old stock frames and hope I get 20 USD for them. A calculation could be 20 % the first year, after that 10 % per year ... not much!
if its the one from the Philadelphia its worth $650
approxx £650 - £650 000
$250
£650 billion and 46p
if its the one from the Philadelphia its worth $650
About 650 gp for each piece
$1,200.
I just bought one for $650.
50-650 usd
$650 to 750
50-650 usd
50-650 usd