picking a truck

Ok, so im a long way away from getting a truck as i cant afford it right now, but i want to know how high is "too high" as far as mileage goes on a truck? I mean, i hear people taling about 150,000 miles on a truck for $5000 is bad, then i hear some say thats good. I just want to get the best bang for my buck.

Imo, mileage is the single most important factor in buying an older used vehicle. High mileage is never a good thing.

High mileage cars and trucks are rarely maintained or repaired properly by their owners in their later life. These owners are trying to wring the last usefulness out of their high-mileage trucks before selling them.

One will often come across a high-mileage truck that has had some recent repairs.
But, high mileage means everything is getting worn out... not just the engine and transmission, but also steering, wheel bearings, suspension bushings, interiors etc... all these things which never normally get repaired. Such high mileage parts just make the truck look, sound and feel like a piece of junk.

I would much rather buy an older, low-mileage truck than a higher mileage, newer one.

If you do not have much money, consider buying a lower-mileage compact pick up truck or a full-size RWD van. These vehicles usually are worth far less when used than a comparable full-size pick up truck. Compact pick ups are imo more fun to drive than full-size pick ups.
Full size vans can do just as much or more work than a pick-up, and have more cargo room /passenger room, too.