A couple things come to mind in response to that question.

1- I recall the day Krystal Hamburger went private and the stock I had purchased when it declared bankruptcy soared. What I was willing to pay for (the value I placed on) the 1991 Volvo Bertone Turbo Plus Coupe I was considering did likewise. It had nothing to do with the car.
2- I recall during the hunt for an SRT6. I found but two black roadsters in the country, mine and another with half the miles. Both were a good fit. However, the lower mileage one was located across the country from me. Given that I like to meet previous owners and do my own evaluation, the value of the far off car was diminished due only to its location. It had nothing to do with the car.
3- Given I do not have appropriate facilities for long term storage of all the cars I would like to own, I am not a buyer which frees me to price it higher than I might if that were not the case.
4- It would take someone awfully arrogant to presume they could price someone else's car without an in-depth knowledge of the particular car, being omniscient or having some sort of clairvoyant skills.
5-They are not making any more. They never made many. The miles are few. The care is evident. This has lots to do with the car.
6- Based on what I learned in high school statistics extrapolating numbers and making assumptions based on small bases often lacks validity. SRT-6s are not like Sentras. Edmunds, NADA, Blue Book, Black Book, auction statistics based on averages do not work as well.
7- I keep hearing "you get what you pay for". In keeping with that potential buyers should be offering a few bucks more if only to get a better car.

Big question. Lots to consider. Many answers but none from me on this one.

Good luck with the sale.