When assessing the price, you must focus on the optical resolution (HD vs. 4K), the outer diameter of the insertion tube, and the working channel width. Higher-priced models typically feature Narrow Band Imaging (NBI) technology, which enhances vascular visualization. Ensure the price includes the CCD or CMOS image sensor quality, as this directly impacts diagnostic accuracy. Additionally, verify if the unit is fully immersible for sterilization, as non-waterproof older models are significantly cheaper but carry higher cross-contamination risks.