cheapest route is to get one from a junk yard or ebay. As far as I know you cant change the mileage on them. So you'll have to find one with close mileage to yours or wait until yours catches up. The dealer would have to flash your truck for some of the functions to work. the steering wheel may be tricky. Although our trucks may be wired for a lot of extras, we can't get most of the stuff to work. Ive read other post were people have added the evic cluster to express model or st trucks and have kept the steering wheel and have been able to access what ever they needed. I'm pretty sure that the compass won't work. You'll need a rear view mirror and wiring from a slt.
2015 Ram 2500 Tradesman, 275/70/18 Fierce Attitude M/T, 18x9 ?wheels, Custom 13' OEM projectors, 55w 5k HID's, 7" premium display cluster swap, Alpine INE-Z928HD HU, RF 200s amp, 2 10" MTX subs, Factory bumper with fogs added