No sales tax, no income tax in New Hampshire. Mil rates for property taxes are about 50% higher in NH for comparable towns, and real estate valuations tend to be much higher for similar properties. Excise tax on vehicles is about the same, NH adds a highway fee. Other miscellaneous fees tend to be higher in NH, sometimes significantly. Plus, tickets and fines in NH are higher than Maine. Another part of that equation is ticket revenue explicitly funds law enforcement budget items in NH while in Maine it goes into the general fund, in other words, police are incentivized to write a lot of tickets.

For all that, if you are poor, it is probably a wash. Maine has better services, lack of a sales tax means your money goes further. If you are middle class, fees and property taxes are going to eat up more money than saving on sales and income tax. If you are wealthy, who cares, your money isn't coming from taxable sources in Maine, and while you're paying more in property tax in New Hamshire it evens out.