You can't really compare prices between markets as supply/demand (and thus the fair market price) can vary significantly between markets. In Texas, for example, there seems to be a huge surplus of Expeditions and most are rust-free for many years. In much of the northeast, however, there seem to be far fewer Expeditions, especially if you're looking for something that hasn't succumbed to the megatons of salt poured on the roads every winter. When you get into ELs, the selection dwindles even further. Add in a luxury trim (eg Limited) and demand goes up because us northerners are suckers for creature comforts. Consequently, a clean EL here in the northeast will still fetch a premium. Auctions, of course, are an entirely different animal. If you're confident that you can handle any and all issues that an auction vehicle may present - or the price is good enough that you would even be ok paying someone else to handle said issues - then that's an avenue to explore.
All of that said, I plugged that vehicle's info into NADA along with your dealer's zip code and he's flat out asking too much. I usually aim somewhere between clean trade-in and retail if buying from a dealer with my target price dependent on what I'm getting for my money. Are there new tires, brakes, etc. on it? Is there a warranty of some kind and what does it include? Have they refinished the wheels and done a full detail that included the removal of all noticeable scratches? In short, you're paying that dealer premium to save yourself the time/money of doing these things on your own. Make sure you're getting some value for that spend.
This is why I basically never want to buy a car in may area again.
I can go a few hours away to nice climate and get 10-15 year old ones with almost 0 rust even on frame and suspension. The people there don't want them! They want newer ones so values are still same as what I would pay here for a rusty one.
I hate salt, water, and oxygen.....logic be damned!