I can agree that he might not find it fun, but it would be plenty safe starting out with a basically new truck, new trailer, new tires and brakes, and as long as he keeps everything in good working order.
The problem is, that's an awful lot of money to risk on something you could very well end up HATING to tow. The closer you are to the limits, the more likely it is you will end up HATING to tow it. You may not notice it at first, because you have nothing to compare to, but after you get some miles under your belt you will start to realize things, things you may not be able to tolerate as time goes on.