Your first post was of a naturally aspirated 7.3 IDI bricknose, 2nd was a base model 7.3 Super Duty, then the one after that a 7.3 SuperDuty Dually. These are very different trucks made to do different things.

Not to sound like a jerk, but you really need to figure out exactly what kind of a truck you want or need.

 

The price is too high mostly due to the fact that it's a dealer.

Honestly, it's worth depends on a few variables, most important of those variables is whether or not trucks like that have survived in your area. Let's assume it's clean, rust free, well maintained, and pretty....if there are no trucks surviving in the region because of rust (salt) and other environmental factors, then it's worth way more than the exact truck in Arizona or one of the dry states. Remember, what it's "worth" is what someone is willing to pay.

Another variable is demand, or how "sought after" a vehicle is. This is area based as well, if you want a crew cab diesel in new York City, it's going to be different pricing than farm country where there are more trucks than people.

All that said, there's no doubt it's overpriced. If you really want it something like that and can't go out and find another, certainly worth the haggle. Whether it's 4k or 6k, up to you to take all things into account and make an informed decision.

I went to a wedding in Vegas a few years ago, I picked up a bullnose 6.9 4x4 crew cab dually for 1500 bucks. No rust whatsoever, interior clean, no body damage, faded paint. I swapped a zf5, turbo, painted it and sold it for 9,000 in new Hampshire. I had it listed for 7k. Demand is king....dude I bought it from said he tried to sell it for months.