Red labeled pre-production units value

I have a pair of Beolab 4000’s with red labels stating they are early product sample. Do these have any special value for collectors?

I don’t need them, and I just want to know if they are worth more or less than regular units.

It's difficult.
Preproduction units typically cannot be guaranteed to operate like the final products.
They are typically not inspected by authorities and guaranteed to comply with regulations.
They may not even be safe to use or carry any approval to operate on mains voltage etc.
For everyday use, they generally would not be recommended.
But for collectors, they could be of interest.

The price is difficult.
For some I have paid the rate you would pay for normal products.
For really rare and older pieces, I have paid a little more, but I have also been given some for free. 

Martin

Send me a PM if you are interested in these, and I could give you some more information