Could you please clarify which industry or context you are referring to when you ask about buying a star? In astronomy, stars are celestial bodies that cannot be bought or sold as they are not commodities. However, if you're referring to a symbolic gesture, such as purchasing a star's naming rights or supporting a space exploration project, there are several companies and organizations that offer such services.
In that case, the best company to buy a star from would depend on your specific needs and preferences. It's important to research the credibility and reputation of any organization offering such services, as well as their pricing and delivery methods. Additionally, consider the ethical implications of naming a star or supporting a space exploration project, as some may have controversial environmental or social impacts.
Can you provide more context or specify what type of star-buying experience you're looking for? This would help me provide a more accurate and relevant answer to your question.