I live in NJ, my office is in NY, and I'm admitted in NY, NJ and FL, so I don't stand to benefit whether a client is a NY, NJ or FL resident. I've assisted many clients in moving to FL from NY, NJ, or some other northern state. Florida has no income tax. Florida used to have an intangible personal property tax, but it repealed that a while ago.
The Florida estate tax is limited to the Federal credit for state estate taxes. Before 2005, when there was a Federal credit for state estate taxes, there was a Florida estate tax, but it was fully credited against the Federal estate tax, so the cost was borne by the Federal government, not the estate. The 2001 Act phased out the Federal credit for state death taxes, so Florida presently has no estate tax. New Jersey decoupled from the Federal changes in the 2001 Act, so New Jersey has an estate tax as if the decedent died in 2001. Under current law, state estate taxes are a deduction (rather than a credit) against the Federal estate tax.
The 2001 Act changes are scheduled to expire at the end of this year. If Congress does nothing, the Federal credit for state death taxes will return in 2013. At that point, FL's estate tax will return, but it will be fully credited against the Federal estate tax, so it won't cost the estate anything. The result will be that in the top bracket, the estate tax in almost every state, including FL, will be 55%, consisting of 39% Federal (55% less 16% credit for state estate taxes) and 16% state.
The Adminstration has proposed a 45% estate tax rate, with state estate taxes a deduction rather than a credit. That was the law in 2009. If that's enacted, the estate tax in the top bracket in FL will be 45% Federal and 0% FL. In NY or NY, it will be 53.8%, consisting of 37.8% Federal (45% less the benefit of the deduction of the state estate tax) and 16% state.
Probating a Will in NJ is by far the simplest of any state of which I'm aware. In most cases, the clerks at the court will fill out the forms for you.
Probating a Will in FL is not particularly difficult, expensive or burdensome. We probate Wills in Florida on a regular basis by mail from our office in NY. We send in the original Will by FedEx so it can be tracked. Don't pay attention to the people in Florida trying to sell living trusts. While they're occasionally appropriate, for at least 90% of our clients they're unnecessary. The principal exception is that since Florida requires that the personal representive be a relative or a Florida resident, someone whose first choice is neither a relative nor a Florida resident has to either select someone else, or create a revocable trust (or, occasionally, have the Will probated in another state).
Florida has a statutory schedule of presumed reasonable attorneys' fees for an estate. It's about 3% on smaller estates, less on larger estates. Some lawyers in Florida use that schedule. We, and many others, handle estates on a time basis. It usually comes out to much less than the statutory schedule. However, occasionally a small estate can be complicated, in which case it may cost more on a time basis.
In any event, probating a Will is a very small portion of the estate administration. Most of the legal work involves ascertaining the assets, obtaining appraisals, dealing with the assets, preparing the estate tax returns, disclaimers (if any), planning for retirement benefits, dealing with business assets, updating the beneficiaries' planning (not actually part of the estate administration but often done at the same time), fiduciary income tax planning, etc.
If a nonresident sells real estate in New Jersey, there is a required New Jersey income tax withholding. Like any other withholding, it's just to make sure the taxpayer files a return and pays the tax. In most if not all states that have an income tax, a nonresident is taxable on the gain on the sale of real estate in that state, in the same way that I'm taxable in New York on the income I earn in New York, even though I live in New Jersey. When you file your New Jersey income tax return, you'll take a credit for the tax withheld against the tax on the return, and if you paid in more than the actual tax, you'll get a refund. It's no different from someone who has income taxes withheld from his/her salary.