12-Core indoor single-mode optical cable is more expensive or 4-core outdoor single-mode is more expensive.

　　Regarding the price comparison of 12-core indoor single-mode optical cable and 4-core outdoor single-mode optical cable, since the price of optical cable is affected by many factors, such as brand, quality, material, production process, and market supply and demand relationship, it is impossible to directly give a clear conclusion on which optical cable is more expensive. However, it can be analyzed from the following aspects:

　　First, the impact of the number of cores on the price

　　In general, the more cores a cable has, the higher its production cost and material cost may increase accordingly, so the price may also be higher. Therefore, in terms of the number of cores, a 12-core cable may be more expensive than a 4-core cable.

　　However, this does not mean that the price of 12-core cable is necessarily higher than that of 4-core cable in all cases. Because the price is also affected by a variety of other factors.

　　Second, the impact of application scenarios on prices

　　Indoor fiber optic cables and Outdoor Fiber Optic Cables may vary in design and materials to suit different application environments. For example, outdoor fiber optic cables usually need to have better waterproof, sun protection, corrosion protection, etc., which may increase their production costs.

　　Therefore, even if the number of cores is the same, the price of outdoor fiber optic cable may be higher than that of Indoor fiber optic cable. However, this does not mean that this is the case in all cases, because the price is also affected by various factors such as market competition and brand strategy.

　　III. Market price fluctuations

　　The market price of optical cables can fluctuate due to a variety of factors, such as changes in raw material prices, changes in production costs, and changes in market supply and demand.

　　Therefore, when purchasing fiber optic cables at different points in time, their prices may vary.

　　IV. Specific price reference

　　According to the actual situation in the market, the prices of different brands and specifications of optical cables vary greatly. For example, on some e-commerce platforms, you can find relatively low-priced 12-core indoor single-mode optical cables and 4-core outdoor single-mode optical cables; while in some professional optical cable manufacturers or suppliers, prices may vary according to specific needs and customization.

　　综上所述，无法直接判断12芯室内单模光缆与4芯室外单模光缆哪种更贵。在购买光缆时，建议根据具体需求、应用场景以及预算等因素进行综合考虑和选择。同时，也建议多比较不同品牌、不同规格的光缆价格和质量，以选择性价比更高的产品。