Hi Daniel,
Old stuff about the past generations of Strida
Depending on condition your bike could be actually interesting for collectors.
To talk about the price you have to find first interested parties I believe.
Personally I’d not ride such an ancient rarity; instead of I’d pin it at the wall, preferred at a place without direct sunlight. Also I’d not recommend to buy a Strida older than version 5 - if it is intended for riding and not pinning 
You noticed that already; several parts of these bikes are not any longer in production since many years.
Some pics can’t be wrong 
Best wishes,
Chris