A bike is worth what ever someone is willing to pay for it.
The price is dependent on where it is advertised.
Ebay can attract crazily high prices but it's a gamble whether or not the 'high payers' spot it.
There are special interest groups who advertise within their membership and depending on their collective views on bikes i.e. to be ridden or to be collected the prices can be stratospheric or disappointingly average.
A quick rake through the internet led back to a previous posting placed here