Is it expensive to replace a timing belt on a 96 Nissan quest,if so about how much,and is it worth it?

i would like to know if the timing belt is the problem,the car does not want to start.the it's like it want to start but doesnt turn over,what do you thing the problem could be,can't get more detail than that.Is it expensive to replace a timing belt on a 96 Nissan quest,if so about how much,and is it worth it?Check battery terminals, loose connections crosion, etc.

Check battery charge

Check if it is completely in park.

Broken or loose conections, wiring in the starting circuit. starter solenoid

Starter motor pinion jammed in flywheelring gear.

Bad starter in general.Is it expensive to replace a timing belt on a 96 Nissan quest,if so about how much,and is it worth it?$300Is it expensive to replace a timing belt on a 96 Nissan quest,if so about how much,and is it worth it?Make sure its in Park correctly, my car is the same and if you dont have it in park correctly and try start it then it wont start, also once my car would not turn over at all, it turns out a spark plug came loose.