SJS, please clarify with your Rav, but I am pretty sure that what you are saying is above the ikkar hadin. If you cannot earn the money without a given expenditure, then your earnings are that much less.
ames, rent food and utilities are not expenditures related to earning an income. Those may be why you need to earn an income, but they are not a result of it. I hope that I am clear in distinguishing between the cost of transportation to a job site (which reduces your net earnings) and the cost of non-earning related expenses. Think of maaser as a 90/10 monetary business partnership with Hashem. You would distribute the partnership earnings after deducting the cost of doing business.
GAW, I’m not sure that the sarcasm is appropriate. I think that the issue of wedding gowns should be taken a bit more seriously. I was always appalled at how form fitting an Orthodox wedding dress is. Just like the sleeve length and necklines are tsnius, the rest of the gown should be too. Why is a kallah allowed to bend that rule (especially since she is automatically drawing attention as it is)?