It might be a good idea to buy a cheap truck, depending on what needs one has and what is available on the local market. If someone requires a truck to haul garbage or heavy equipment from place to place, a reliable used model might be available nearby that is cheaper than the shinier, newer models available on the lots of nearby automotive dealerships. However, a cheap truck may not be as cheap as it first appears.
Cheap trucks are often also used trucks, and used trucks come with a number of maintenance concerns. A used truck should be inspected by a trained mechanic before a decision is made on purchasing it to avoid buying something that will cost more in repairs than it cost to purchase. Doing a CARFAX check on a given vehicle can reveal major problems that the seller may not be telling potential customers.
Overall, cheap trucks are a good idea only if someone is on a budget and they are mindful of the problems cheaper vehicles can have. People looking for a truck that don't need to worry about money should look at newer models, so they don't have to worry about buying new parts and repairing a vehicle that they need for a specific job.