When sourcing FRP, the price is heavily influenced by the resin type (Orthophthalic, Isophthalic, or Vinylester) and glass content. You must verify the glass-to-resin ratio, as a higher glass content typically increases mechanical strength but affects the price. For structural applications, ensure the product meets ASTM D790 (flexural properties) and ASTM D638 (tensile properties) standards. Additionally, check for UV stabilizers and fire-retardant additives (like ASTM E84 Class A rating) if the product is for outdoor or industrial use.