The question becomes, are you wanting or looking for a 1964
If you're dream trailer is a 1956
Safari Front Kitchen or a 1966
Overlander, then you might be willing to pay far less. If you're looking for a 1964
Safari to redo, how much time/money/effort are you going to spend running around the country looking for one vs. the one in your backyard? So, you maybe willing to pay more.
Are you flipping or keeping?
The trailer could have a range of $1,500-$7,500 depending on who and how bad they want it. Me, living in Virginia, I wouldn't give you more than $750-$1,000 because of the cost of travel down/back to get, and would do nothing more than to try and flip it for $3,500-$5,000. But, if I lived 25 miles away, might go to $1,500-$2,500.
Not sure that helps, but it comes down to this. Somewhere between list retail and getting the trailer free, I'm sure there's a number everyone can agree on ;-)