Buy in to is a phrase that is often used in business scenarios, and it refers to the willingness of individuals to embrace or accept a new idea or strategy. If you're trying to avoid using this phrase more often in your writing or speech, there are several synonyms that you can use in its place. These include 'subscribe to,' 'believe in,' 'support,' 'endorse,' 'embrace,' and 'invest in.' Each of these terms encapsulates the same idea of agreeing with and committing to a plan or idea, and they can be used interchangeably depending on the context. Whether you're writing a professional report or engaging in casual conversation, these synonyms can help you convey your message clearly and effectively.