Hello! If you are looking to buy a Facebook account that appears legitimate and has been active for at least 3-5 years, it's important to be cautious. Purchasing or selling Facebook accounts is against Facebook's terms of service, and doing so can result in the account being banned or disabled.
Instead of buying an account, I recommend focusing on building and maintaining your own Facebook account organically. You can create a new account and gradually build up its credibility by posting regularly, engaging with others, and growing your network of friends or followers.
If you have any specific questions or concerns about using Facebook or growing your account, feel free to ask!