I'll vote 5-6K asking price; considering clean undercarriage but lack of service history and known TB/WP overdue.
For context, I've been doing extensive nationwide searching for the past 2 months and considered anything from 98-07 with ideally less than 250K. Considered well maintained, 300K options as well. It does seem the demand for 300K plus vehicles is low, based on how long those listings sit on the market. Strictly based on my findings, 8K would be on the high end of asking but not completely unreasonable.
I almost purchased an 05 from a mud member (Phoenix area), with excellent service history and 295K. Undercarriage saw a few years in MT and UT, so not AZ/TX clean, but still very good. Vehicle was due for TB/WP and needed a new AC condensor (parts included). Came with gamiviti rack and relatively new Falkens. He was trying to get 7-8K, but was unsuccessful. He ended-up keeping it.