On one side, its pretty obvious that the most important things in life cant be bought, for example love, happiness, or to be more concrete, having a baby, or getting married, or even things as simple as receiving a big smile from someone we love. All these things are payless and are worth more than any jewel or car or house or anything material. Also, weve always heard that money cant buy happiness, and were always seeing famous actors who have everything they want, but they have depression or even sometimes kill themselves because they are so unhappy.
On the other side, on most cases, money can help us enjoy more those valuable moments or feelings. For example, if someone has a baby but doesnt have money to feed the baby or even give him or her a warm place to live, that person will surely be suffering a lot, despite the happiness that means having that baby. Even if this is an extreme case, there are a lot of situations where not having money can prevent people for enjoying things that are free. For example, people who have lots of debts or people who cant afford a good education for their kids.
I think that indeed the best things in life are free, because there arent material things that can be compared with watching a sunset, or receiving a hug or an unexpected phone call. Even more, I think the best thing in life is love, and love will never be something we have to pay for.