Half of what BAMW is asking is usually a good starting point if you are looking for a rider, as opposed to a" investment quality museum piece" or however it is BAMW describes his bikes.
Then you might do a realistic plus or minus on that figure, adding in for the desirable extras like those Rob has pointed out , and deducting for the things you will have to replace to get it roadworthy.
If you can't hear it running and have a test ride you should also add in for the risk you take, you can probably learn from dealers here as they usually offer next to nothing for non runners.
For example, the tyres look unused, but they may be five years old and past the manufactures used by date.Etc Etc-----.
It would also be a help if you were able to speak to the person who did the " partial " restoration - it is nor uncommon for restorers to do a "museum" quality resto with all work cosmetic and no consideration give to mechanical's whatsoever.
But it looks a nice bike, and in the end it value is what you are happy with.
I paid $800- for a high mileage and scruffy Funduro and have enjoyed spending whatever it takes to get it the way I want it, but an associate is even happier with the immaculate low mileage Funduro for which he paid a dealer almost $6,000-.
I suspect that the present owner has built up his collection with an eye to speculative capital gain, and will be well aware of what people like BAMW are asking, so most of the information on this thread is probably not a lot of use - he probably has a figure he is not going to go below, and this is probably 90% of what BAMW, etc, are asking -----------.
Please note that this is not meant as criticism of BAMW - I dont doubt that his bikes have been professionally restored to the highest standards cosmetically and mechanically and his prices do no more than reflect the cost of doing this professionally.
It is just a pity that owners of lesser bikes seem to think that their bike which may not have relieved the same treatment are worth the same as BAMW'S immaculate bikes!