Biomanufacturing is one of the strategic emerging industries in China during the “14th Five-Year Plan” period. The author once proposed “Tao-Fa-Shu-Qi” for the industrial biomanufacturing and provided its philosophical guideline. Focusing on the “Fa” of biological manufacturing and further analyzing the concept of “Fa as rules” in biomanufacturing, the author first proposed the concept of “Price to Cost-of-raw-materials Ratio” (PC value), which is the ratio of product market price to cost with raw materials. Biomanufactured products can be categorized by PC value into high-value products, value-added products, biocommodity, and products for public good. The PC value is a key indicator for evaluating the technological capability and economic viability of biomanufactured products. It is simple, transparent, and publicly accessible, offering a new approach for categorizing biomanufactured products. This indicator aids in guiding new technologies towards pathways of efficiency enhancement and cost reduction, forecasting future manufacturing costs and market prices for bioproducts, and assessing the industrialization potential of emerging biotechnologies. This article focuses on the biomanufacturing of fructose syrup, fructose solution, crystalline fructose, allulose, myo-inositol, and tagatose as examples, analyzing pathways for developing new technologies and predicting their economic feasibility. The calculation and analysis of the PC value could provide a new methodological tool for the top-level strategic design of the future development of emerging biomanufacturing industries, and could effectively facilitate the high-quality development of the bioeconomy.