It only cost me about $50 for the front and $50 more for the rear pads. I can change them in a hour. Less time if you are switching from winter to summer tires at the same time.
I would replace the pads, well before they get thin. Once thin, they can not dissipate the heat nearly as well as new pads.
I do not like replacing the rotors. I had to do that on a Chrysler minivan. By waiting until the pads where worn out, then I needed to spend $75 for each rotor. I would have saved a lot of money by changing the $35 set of pads much earlier. At least those rotors where very low cost at Napa. Your pickup rotors would be much more expensive.
I would also highly recommend going to the Ford dealer, pick up a quart of the class A motorhome rated brake fluid. It has the highest possible "Wet boiling point" of all brake fluids, and replace the brake fluid. After about 5 or 6 years, the brake fluid has the opportunity to absorb a lot of moisture, and should be changed. The old brake fluid can reach 700F and some moisture in the fluid can change to steam bubbles, that can compress, giving a "Spongy" feel to the brakes. Changing the fluid every 5-7 years will prevent this.
Good luck!
Fred.