By living in JC, you no longer pay the ~4% NYC city tax on income. NJ state income tax bracket rates are also lower than NY state.

JC downtown/Newport is also a special zone where you only pay 3.75% sales tax shopping in person. 6.65% sales tax for items shipped to you.

Foods cheaper too.

If you have an HSA though, those contributions do not lower NJ income tax ability.

Overall, it’s a win win living in JC vs Brooklyn. More take home pay and expenses are lower so you’re saving on both ends. Even path from Newport/grove/exchange place/journal sq is more pleasant of a ride to get to midtown or WTC than MTA.

Only downside is higher property tax so renting is a better deal if you’re just a single person. Lots of high rises coming online soon so too so hopefully supply outpaces demand.

Let me know if you have any other questions, I build payroll software so this is my wheelhouse and my partner and I did the math a year ago when deciding to move to JC or NYC