When assessing the price of Non-Destructive Testing (NDT) X-ray equipment, you must prioritize the Tube Voltage (kV) and Focal Spot Size. Higher voltage (e.g., 160kV to 450kV) allows for the penetration of thicker materials like steel, which increases the cost. A smaller focal spot size (measured in microns) ensures higher image resolution and clarity, which is a premium feature. Additionally, consider the Digital Radiography (DR) vs. Computed Radiography (CR) technology; DR systems are generally more expensive upfront but offer faster imaging cycles and lower long-term operational costs.