$4,000 would be a very high asking price for the East coast. I bought my K6 in 2012 for under $4k. It had a top box, centerstand, handguards, crash bars, and 10k miles.
Unless the bike is decked out with the best of everything, I think you're in the $2000-$2500 territory for my market (mid-Atlantic).
It's dumb, but higher mileage bikes are worth less mostly because there are so many low miles ones out there. By the time a future owner wears out your bike, we'll probably be close to the end of the combustion engine era.