When comparing prices, you must look beyond the cost per kilogram and evaluate Hardness (Shore A or Shore D), Tensile Strength, and Elongation at Break. Prices vary significantly between TDI-based and MDI-based polyurethanes; MDI is often preferred for its lower toxicity and better environmental compliance, though it may carry a premium. Ensure the supplier specifies the polyol type (Polyether vs. Polyester), as Polyether offers better hydrolysis resistance while Polyester provides superior oil and abrasion resistance.