Between 6-13K going by current asking prices on Carsales.
Note the search includes MY04 3.0r-b meaning your car whilst desirable to the 6mt Subaru H6 enthusiast isn’t really the first of anything nor particularly rare?
https://www.carsales.com.au/cars/subaru ... r-b-badge/It’s the test car for what publication and do you have supporting evidence?
As for what your example is worth, it’s largely condition and presentation dependent.
The price will reflect the previous ownership, mileage, condition and *presentation* based on general market price, availability and desirability of the cars specification.
As such, all you need to do is document the cars condition with *considered* photos, and get the cars story straight for the description.
Then ask the price you think it’s worth but mention the price is negotiable to the right buyer, preferably an enthusiast or collector.
You can then reduce the asking price incrementally on a weekly or monthly basis to show you’re motivated to move the car on.