Chances are that 250 will be overloaded on the rear axle hauling the 279. $600 per month for 4 years is a HUGE commitment of capital. Good luck and personally I wouldn't dump a ton of money on a machine that has the "potential" to make money. My first skid was an 1835 Case that helped build the colonies in America. It was cheap and worked fine for what I needed it for, you don't always need an expensive piece of equipment to do the job.