Salvage titles on a vehicle isn't always a bad thing but yes having a salvage title on a vehicle does affect the value of the car negatively.
A Salvage Title can drop the value of a vehicle as much as 20% to 40% off the blue book value.
So whatever the blue book value says your current car is worth you should drop 20% to 40% off the value of the car and that would be the approximate value of the car with a salvage title.