It's a role-playing game. You can get married in it with no real feelings; it's a part of the game. Not everything has to be benefit in my opinion. If you have lots of money, you're on high level and dont feel like leveling, don't really need money, you could try this just for fun for example with your linkshell friend. Just something to work with your LS group. I myself also doubt I'll ever be that rich that I could even consider something like that, but yeah, as I said it's a role-playing game where you can play role of being married.