Before buying an airbrush, you should consider several factors. First, determine the type of airbrush you need – gravity feed, siphon feed, or side feed. Consider the purpose of your airbrushing projects and choose the appropriate feed system. Second, assess the nozzle size and needle combination. This will determine the level of detail you can achieve. Third, evaluate the airflow control options and the air pressure range supported by the airbrush. Lastly, check for the availability of spare parts and accessories, as well as the brand’s reputation for quality and customer support.