Which of the following is NOT a source of price comparator?

The choice identified as correct refers to a source that does not directly relate to comparing current prices. Market demand forecasts primarily provide insights into expected future prices and market conditions rather than serving as a direct reference for assessing current prices.

In contrast, prices that have been paid in the past, published prices, and competitive bidding all present concrete data or actual figures that can be leveraged to compare and evaluate pricing strategies. Historical prices offer a baseline to understand price trends, published prices often serve as standard benchmarks within the industry, and competitive bidding reflects the current market landscape by showing the prices that competitors are willing to accept. Thus, market demand forecasts do not serve as a direct source for price comparison in the same regard as the other options.