Love is an emotion that is priceless and eternal. This beautiful feeling cannot be measured by the monetary value. The phrase "Love don't cost a thing" emphasizes that love cannot be bought or sold with money. There are various synonyms that can be used instead of 'Love don't cost a thing,' such as 'Money can't buy love,' 'True love is priceless,' 'Real love is not for sale,' or 'The best things in life are free, including love.' These phrases remind us that love is a divine feeling that comes from within and cannot be purchased with money or material things. It is a valuable lesson that everyone should keep in mind.