So, I put this question before a law professor at Pace named Bridget Crawford who specializes in tax law, and she told me that the IRS decides what the asset is worth.

"There are a variety of accepted valuation techniques," she said. "The classic definition of fair market value is what a willing buyer and a willing seller would agree to." She added that if there was a dispute, it would go before a tax law judge. That said: "It’s never happened that there has been a valuation dispute about the right of publicity – it’s completely untested."

I never figured out whether there's someone in particular at the IRS who would be responsible for making these calls, but I guess there would have to be, right?

I should note: Crawford argues that it's possible for legislators to write postmortem publicity laws in a way that would avoid saddling heirs with huge tax bills. As I understand it, this would involve taking away the celebrity's right to decide who gets the asset, and instead requiring that it pass to a particular party, like, say his/her spouse and children This would make it a "survivorship right," and it would mean that the asset doesn't get taxed in the same way as a normal inheritance.

Here's the quote from Crawford: "There’s a compromise there... By trying to protect the celebrity’s right, you create a huge tax problem but the only way to avoid the tax problem is to take away some of the very right you’ve just created."

W/r/t Elvis impersonators, my understanding is if you're making money off it, you have to get their permission and pay them for the privilege.

Boston's great! I live in Central Square as well.