The current price level of light-duty, full-size pickup trucks has been like this for the last several years. Most brands sell half-ton that can be equipped to reach MSRP in the $70k range (check out Sierra Denali Ultimate trim). The 6.2l engine in GM line up requires a high trim level, LTZ is a minimum in Chevrolet and SLT in GMC.
MSRP is one thing, but the discount is massive. I've been running a scenario for the third year now to spend a small amount of money every year to be able to drive a new truck. So, while the MSRP seems monstrous, it's not so bad in the bigger picture.
Corrosion problem is not just in the body, but more importantly in the frame. Ford aluminum body panels address only one aspect, the rest of the truck uses mainly steel. The aluminum panels also carry a more expensive repair cost in general, but it should not be by much.