Which of these factors is not a price determinant?

The factor that is not a price determinant is the "Standard of living". The standard of living refers to the quality of life and the level of material comfort that people enjoy in a particular society. While it can indirectly affect pricing, it is not considered a direct determinant of price. On the other hand, the other factors listed - level of market demand, economic trend, and competitor's price - all directly impact the price of goods or services. The level of market demand determines how much consumers are willing to pay for a product or service, while economic trends such as inflation, recession, or boom can affect the supply and demand balance, and ultimately influence prices. Additionally, competitor's prices are also a critical determinant of pricing decisions, as companies need to be able to price their products competitively to remain relevant in the market.