When comparing prices, the most critical factor is angular accuracy, typically measured in seconds ("). A 2" accuracy theodolite will command a higher price than a 5" or 10" model due to the precision of the internal optical or electronic encoders. Additionally, check the telescope magnification (standard is 30x) and the minimum focusing distance. Higher-priced units often feature dual-axis compensation, which automatically corrects for tilt in both horizontal and vertical planes, ensuring higher reliability in the field.