Time for a new truck?

Hey all, looking for advice on my 2008 F150 2008 F150 . I bought in 2011 for $18,000 CAD with 180k (all highway) and it was in excellent shape when I had mechanics mechanics looked it over before I bought it, they said it was like brand new. Now fast forward to 2017, it now has 264,420k on it and I've been told by a garage that it needs $4,000 in repairs, its worth between $2-3700 according to Kelley Blue Book, it has rust everywhere. I've been told its nearing the end of its life and I can expect maybe a year tops more out of it, again this is what a garage told me and I know they want money so I don't know how accurate that is. Not sure I want to invest anymore money into a vehicle that's not worth that much.

Two scenarios exist: One, I fix only the immediate work needing to be done,
and hope it lasts until I can find a new truck or it just falls apart, the garage also added that I could do all this work just to have something else break because of the all of the rust underneath the vehicle. Second, I could just get a new truck or used vehicle.

Any advice? I really am in a pickle I feel, so thanks for any input!

I didn't find the right solution
References:

https://www.truckforums.com/forum/general-truck-tech-42/every-truck-manufacturer-swears-out-do-others-21429/

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