The first time you get stuck without cell coverage, and without something large enough to drag you out (winch, another truck, etc), the cost difference becomes meaningless. What most people don't realize is once you are not in flat country, snow and ice actually becomes a PITA. Having actually put chains on and off in the Sierra's in slush, I can tell you it is money well spent. If you are never going to get more then a few truck lengths off dry pavement, it is a near total waste. If you plan of covering the sides of the trailer in mud from time to time - or tow on a beach, 4 go tires are better then 2.