Hard to say. Sounds like you have decent miles for an 11 year old truck. I guess it all really depends on what you are going to disclose to a potential buyer.
There are a lot of used Explorers floating around and I'm not 100% sure I'd want to pay much more than $4k for one with an accident history that may need a new fuel pump soon.
On the other hand when I got my wife a new car 2 years ago we were offered $1500.00 for our used 02 WRX. It had 168,000 miles on it but was a one owner accident free, female driven car. We passed on the dealer's offer and sold it for $3800.00 privately.
Ya never know