I bought my Titan about 6 months ago, it's on 06 with 122k with great maintenance records. I love it, and haven't had any big issues so far. With the mileage you're looking at, plan to change out normal maintenance parts so account for that in your purchase budget. So far for peace of mind I've changed out the plugs, all filters, changed all fluids with amsoil synthetic, and axle vent mod. I also had motor movement so I replaced the transmission mount, and currently changing out motor mounts. Made a HUGE difference.
ALLBLACKTITAN nailed it, my axle seals are leaking which I'm not stoked about, but so far no cracked manifolds.. Yet. But the truck is phenomenal. Nissan's rockford fosgate system is killer, and the truck rides better than any other brand I've driven before. It's got power for days, and is just overall MUCH more refined than the other trucks of that generation. Honestly, aside from the diff failures, cracked manifolds, and leaky rear ends, the titan is solid. My old silverado ticked like crazy, and their trannies never had a good reputation. Fords and Dodges don't even need to be explained, they just flat out break more often. (Not trying to start an argument, just making an observation from friend's past experiences.) And all their interiors are archaic compared to the Titan's.
Good luck, just don't jump on the first good deal you find. With that mileage, MAKE SURE it has a solid maintenance record, and inspect for the obvious signs of misuse and leaky areas. Happy shopping!!