Gasser maybe 6 or so guarts of oil, compared to 10 or more in the diesel, and generally they like to pork ya an extra buck or two for that "special" diesel filter. Also, if you're wise, you're changing that fuel filter often! Not a big worry on a gasser, so I think twice as much isn't that far off.
Hey, I'll trade ya an 02 CTD with only 230K on it straight across??? Come on, clean one owner, and has new fuel pumps too!
Like I said, these are HARD miles. You found a rare truck, that was obviously babied, and taken care of. The last owner probably could have gotten by with a Tacoma, but just had to have that big ol diesel. Most of us, and I think you are one too, don't really need it.
My present F*** V-10 Shorty replaced my PS stretch-cab dually. The PS was exactly what I needed at the time. Now, the V-10 is even more then I need. Bad part is, the big three leave no real middle ground. You can have thier oil burners, or thier big blocks, but nothing slightly less then that.