My truck is a salvage title. Almost walked away due to that alone. But... I did my homework and scored a great deal.
Info: Up here, my insurance would reduce payoff value by 20% for the rebuild title. No dealers will take it on trade.
Insurance decides if a vehicle is "totaled" or not. Almost always comes down to cost to repair vs cost to replace. My co workers Honda was stolen and stripped of body parts. Car was fine otherwise, but "totaled" by the insurance company because in their books, it would cost more to fix than payoff. So he bought it back from them, bought secondhand fenders, etc, had it painted, and got a great car for hardly any dough.
My truck was rolled, and I used the seller (very open with me; gave me pictures - showed me before, during and after photos of the work) and a buyers inspection to make my decision. Supply and Demand will typically drive prices in a given region. I was unwilling to buy an out of state truck, so I paid more for mine than I would have if I had bought it in some other state where demand is lower. Do your homework, and you can't go wrong.