No, it shouldn't be equal parts.

Consider, what do "average" men typically gain from a relationship with a woman? Emotional servitude, domestic slavery; cookery, housekeeping, potentially child rearing, sex, companionship, the list goes on. But what does a woman gain, since she is losing the time, effort, and personal investment in the aforementioned? Not a fucking thing.

There are three types of people who are going to argue this fact: men, women to young and stupid to know better, and women so trampled by their husbands they have transmuted their marital misery into male ass-kissing in the desperate hopes that their porn addicted husband will love them again.

And all three deeply wrong parties will insist until that not all men are emotional sponges who can't wash their own assholes without Mommy 2.0 instructing them, and in a way, they are correct. There are SOME men that aren't like that. Some, as in not the majority. The exception to the rule.

And an excellent way to weed out which men are those men is to refuse all forms of exploitable benefits, financial or domestic. There's no need for 50/50 if you've found yourself one of these so-called "good men" because if he is one, he will have his shit together and therefore he doesn't need you to give half of your shit to compensate for his inadequacy.

Your presence in his life is a GIFT.

His presence in your life is OPTIONAL.