Dont forget tax!

Try:

$ echo "(93250.1)+(13000-9325)0.15"|bc

gives tax payments on 13k USD to IRS 1483.75

9% of take home pay is

$ echo "(13000-((93250.1)+(13000-9325)0.15))*0.09"|bc 1035

Then there is the additional sales tax at point of sale, which can further reduce buying power.

Yes its 135 than your projection, but that might be food for the week.