Under the bill of quantities pricing system, construction contractors may employ unbalanced bidding to optimize profits or even engage in malicious speculation. The high complexity of hydraulic engineering makes project changes inevitable, exacerbating investment control risks for construction units. Current domestic and international practices for change items adopt the "cost + profit" pricing principle, which fails to effectively curb profit transfer in bidding. Combining contract dispute case law and quantity pricing standards, this study proposes a generalized "cost + profit" unit price approval principle and establishes a dynamic pricing adjustment mechanism to mitigate arbitrage risks arising from the combination of unbalanced bidding and project changes.
