This is not entirely true. In a marriage relationship, when a spends for his wife, it is expected as there cannot be love without giving.
But when a young girl gives herself to a man who is not married to her, he sees her as a sex object that satisfies his sexual urge. This will make him spend so much money on her. It's not that he loves her, he only lusts after her body and nothing more. Deny him sex for at least two times and see if those nice and expensive gifts will keep coming.
For the girls, understand that you are somebody's wife and keep yourself. Don't be deceived by those expensive gifts.