What is the point of getting married?
If two people want to be together, because life is better together than apart, let them be together.
If two people don't want to be together, because life is better apart than together, let them not be together.
If you can do that same thing, without substantial entry and exit costs (wedding planners, churches, lawyers, etc.), then why not keep that wealth and spend it on your relationship and family instead?
The only reason a "CONTRACT" as opposed to day-to-day at-will partnership agreement would make sense, is if ONE of the partners KNOWS that the OTHER will NOT prefer to voluntarily be together with him or her.
If everyone is happy, there's no reason for anyone to leave or walk away. But if you KNOW the other person won't be happy down the road, then insisting on a contract makes sense.
So, I'm always really highly skeptical and put off by people who insist on contracts. If I'm a tenant, and I pay my rent on time, and I don't start problems, every landlord wants me. So if my landlord sucks, I want the freedom to walk away and be happy with my life. If I'm a landlord, and I fix any problems my tenants have, and I've very flexible and understanding of their situations, every tenant wants me. So if my tenants suck, I want the freedom to get rid of them and be happy with my life.
BUT! If I KNOW that (I, not the other person) sucks, I want to lock-in the other person. I know nobody will want me down the road, so why not get someone to agree TODAY, RIGHT NOW, THIS SECOND, that they want me, once and for all, and be bound to the consequences forever? I don't want to have any incentive (or burden) or making the other person happy. The higher the cost of them leaving me, the less I have to worry about them being happy. In that case, a contract makes perfect sense.
So, I don't think any age is a right age to get married.