I wouldn't buy a car that's been tracked or I'd certainly ask for a big discount. 
Sure its only been tracked 4x but most likely driven incredibly hard on the street  everyday. 
What are the risks of track use? Clutch seriously worn/overheated. Brakes cooked. Wheel bearings overheated. Suspension worn. Engine overheated. 
No thanks. The last thing I want is someone else's used and abused vehicle.