The fuel filter is in the tank as part of the fuel pump/gauge module. When I replaced mine in a Ram 1500 a few years ago the best deal was around $300 for the part because it was serviced as part of the module, and that wasn't retail.
But I just looked up the price of the filter, and now it seems that it's available separately for about $35. You drop the tank to remove the tank module. I'm assuming it's the same as the pickup model.