that looks like a very clean looking 99-07
out of state truck or some old guy who hardly drove in the winter ?
if it is clean , fluid film the heck out of it , preserve what you have
the weak points on that year range are , brake lines , trans cooler lines , fuel line and evap line, door handles , the right front quarter panel has a spot that is the first thing to rust out about 12 oclock over the passenger front wheel
and rear spring shackles , tail gate hinge hardware
most of those are rust weaknesses
rocker panels and cab corners are a place for rust also
other than the door handles if you keep all that from rusting you are golden and a set of door handles is 20 bucks and not hard to change out when you break one.
if you set the blend for the AC all the way to cold and it chirps , it is the blend door stepper motor it doesn't detect it is all the way shut and keeps tryin , click up one notch from the bottom and it stops.
the only real expensive issue I found is the insterment cluster the traces lift up for the speedometer stepper motor , it is a pain and the solder around fix only lasts around 6 months a new cluster is 3-400 and is the same thing , much easier to buy a 30 dollar GPS based speedometer stick it on the dash and plug it in to the cigarette lighter and get back to driving.
I have 2 of those now in my 98 and 04
for the fuel and evap lines you can buy bulk poly and ends and make new lines the factory were overly complicated mult part lines that are expensive.
again most of it's weaknesses are rust , keep it coated with fluid film or similar.