1) you expect he has to pay more than you even though you earn double than him.
2) you count money very much. I think half half is so fair. besides, you earn much more.
3) he just earns 15k but he pays the most part. you just need to pay for school fee and food, not too much. you must save a lot of money.
he thinks of saving money for himself and you also thinks of letting him pay all and you save all money.
being husband and wife. i think we can't calculcate very often.