The antonyms for "buys a one-way ticket" can vary depending on the context in which the phrase is used. In the literal sense, the opposite of buying a one-way ticket would be to purchase a round-trip ticket. However, in a figurative sense, the opposite might refer to someone who is uncertain or indecisive about their plans and refuses to commit to a specific direction or destination. They might choose to remain stagnant or even backtrack in their journey. Alternatively, someone who purchases a multi-destination or open-ended ticket could be seen as an antonym to one who buys a one-way ticket, as they are open to exploration and adventure.