OP, stay away from "bargains" that appear to be oil patch trucks, construction company trucks and rental outfits. Generally white trucks, low optioned and might seem attractive with relatively low miles for the price. Avoid like the plague.
I would be less leery of public agency trucks though, city, state, etc, but still cautious.
Another avenue for a deal on a truck is branded or salvage title vehicles. Again, caution to be taken, but there are MANY salvage vehicles that are in great condition and generally if the truck was repaired years ago and has been in service for quite a while, any "issues" with the repairs are behind it. Bonus points if it is verifiable as a theft recovery, body damage only, minor ish damage with airbags requiring it to be totaled or a soft roll and you can verify it. This will require more skill and intuition that you're not getting a POS though. But an option.
Personally on a seriously limited budget, when I search for a vehicle under that criteria, I don't stop until I found a 1 owner "grampa" vehicle. They come up often but sell quickly, so be ready to jump.
But that goes for any decent deal in the current strong economy.
And as mentioned before, I'd consider the low retail value of 2wd trucks. Anything with a good LS or rear locker and the right tires will take you most places with much more money left in your pocket!
