Why do prices of consumer products seem to rise independent of their supply? For example, in my country, the price of coconuts steadily rises, despite the fact that we still have plenty of coconuts. The same with vegetables.

Is this caused primarily by an increase in the cost of labor as a factor input, or are other forces at play?
To make it simple: let say your coconuts production is constant over time but the population is growing. It's a constant supply but an increasing demand, resulting in an increase of coconuts price.

If the prices were constant, the demand would be higher and thus not fully satisfied.