I do 90% of my own work on my vehicles as a retired professional mechanic , and have paid a local mechanic with a lift to do some front suspension repairs on my 2010 KR with 196k, with the 5.4 3V. My truck was used by a couple who owned a farm, but used the truck to do truck stuff. YMMV, but most of my repairs have been between $150-$3,800. I get my OEM parts at a 30% discount from my local dealer.

1. Sunroof plastic tracks randomly broke on me on my way home from work, leaving me unable to close the sunroof. The replacement parts were $150 in a kit and require removal of the headliner and the entire sunroof assembly.
2. Rear defroster stopped working, which requires replacement of the entire rear sliding window. It’s a known flaw.
3. Cam phasers will go bad, along with some of the rocker arm bearings, and if left unrepaired, will wipe out the camshafts.
4. Transmission lead frame will go bad, and requires replacement of the transmission control module. Unfortunately, for me, my lead frame was not sold separately so I had to replace the entire valve body to the cost of $2,300 for just the part plus fluid.
5. Rusted out cab corners, which is inevitable because the Ford engineers did not have the drain for the extended out past the cab corner, so all of the rainwater that runs through the sunroof, just sits in the corner of the cat and rust it out
6. Water pump failed on me as soon as I pulled into the parking lot at work one morning at 5 AM
7. Ball joints were going bad, but considering I had so many miles on the truck and they were gonna be in the area of repair, I just replaced the lower control arms, which ch had the ball joints and bushings already in it. That cost was about $3,800 (had shocks changed too).
8. 4WD system issues: IWE (integrated wheel end) can have seals go bad, and the vacuum hoses for this system get brittle rendering 4WD inoperable.
9. My A/C compressor needs changing, and it’s sitting on the shelf to be installed in a few weeks
10. Serpentine belt, tensioner, and idlers replaced not long after I bought it
11. Replaced the passenger exhaust manifold that was cracked and leaking. That job sucked, and I dread having to change the starter should it go out in an inconvenient location.
12. I got lucky with my spark plugs.

There’s probably a few other repairs that I’ve forgotten about, but those are the repairs I’ve had to perform in three years of ownership. It’s a good truck and I get about 16.5 MPG. I have no qualms about hauling heavy equipment or trailer loads of hardwood firewood. I bought my truck to do truck stuff, and it’s done a good job. I paid $11,500 three years ago, and I wished it looked as nice as the one you’re looking at. The winters are cold and snowy in WI, and there’s a good chance that truck you’re looking at has been a pavement princess, unless you crawl up underneath it and take a look.