The most appropriate homonym for the given sentence is: soar

The correct sentence would be: "With time, the prices of essential commodities soar high, beyond expectation."

Here's why:

• "Soar" means to rise rapidly, which perfectly describes the sudden and significant increase in prices.
• "Sour" means to turn sour or become unpleasant, which does not fit the context of increasing prices.
• "Sure" means certain or confident, and it doesn't fit the meaning of the sentence.
• "Sore" means painful or injured, and it's irrelevant to the context of rising prices.