When sourcing used equipment, prioritize structural integrity and mechanical functionality. For cardio machines (treadmills, ellipticals), check the motor horsepower (continuous duty rating) and the mileage or hours of use on the console. For strength equipment, inspect the weld points for cracks, the thickness of the steel tubing (minimum 11-gauge recommended), and the condition of cables and pulleys, ensuring they are free from fraying or resistance. Always verify if the equipment is 'As-is', 'Cleaned & Serviced', or 'Remanufactured', as this significantly impacts the lifespan and price.