If its an auto I dont think it can be flat towed, As to towing FWD vehicles many do and I do but ours is a manual trans that can be. The murano as you noted cannot be towed but has to be trailered.
Weight the car to know what it does weigh and yes you can get a tow dolly fairly cheap used or at CW. Check craigs list for used stuff do not buy new if avoidable as you will take the hit to sell. When you check CL use an expanded search to near by states also. Measure the tire width outside to outside, then add the fenders to know which one you need. Several have posted before about buying only to find it too narrow, one with surge breaks would be nice.