If your stock gears are 3.92s and you are running stock or close to stock size tires, don't tow much and don't care about the track, then you are probably right. Probably not cost efficient to change gears.

The TruTrac is I'm guessing about $550, installation is gonna take a good shop about 1.5-2 hrs. to do the install, so you should have no problem staying under a grand for the total job unless your labor prices are just totally ridiculous out there.
Also, if money is tight, you can also look at the Auburn LSD, it usually runs close to $150 cheaper. I've had two, in two different trucks, and they are fine. The "crap" you hear about the clutches wearing over time maybe true, but I had my old set for 68,000 miles and they worked just as well the day I sold the truck as the day I put them in.

In all honesty, I'd buy the TruTracs now, but mainly just to see how different they are. I was going to try them in this truck, but at the time I did the gears, Detroit was being bought out by Richmond Gear and production was shut down. Would have been an estimated 4-6 weeks to get one, didn't want to wait.

ALL reports I hear is that both work fine, the TruTrac lasts longer, but the Auburn clamps faster, which is why you see all the "track" 4x2 guys with the Auburn and just about everyone else going with the DTT.
As an off-roader who ain't been to the track since the late '80s, I prolly shoulda went with the DTT, but over-all, I'm very happy with the Auburn...

 

Auburn here also and no complaints