When Prince died, Megan Mahn Miller felt the same shock and sadness shared by many Minnesotans. But because of her profession, she also knew what would inevitably follow: a flood of people buying and selling Prince-related memorabilia, some of it authentic, and some just a moneymaking scam.

“As an appraiser and auction professional, I run the risk of looking like an ambulance chaser if I start discussing the crass realities of property, money and death,” she wrote in a blog post on her website (mahnmiller.com). “Here is the reality. When a celebrity dies, more of their memorabilia hits the market.”

Grieving fans want to possess a link to a celebrity they loved and admired, and others see an opportunity to cash in. “Some are legitimate, but some are criminals.”

Mahn Miller of Minneapolis is an expert on celebrity memorabilia. She’s a property specialist for Julien’s, a California-based auction house, and she also runs her own appraisal company, Mahn Miller Collective Inc.

“The rock’n’ roll memorabilia market is insane right now,” she said, and a sudden death of a high-profile musician can trigger a buying and selling frenzy.

Would-be collectors need to take a deep breath and avoid buying on impulse. The value of a Prince artifact is determined by the same factors that determine value for any piece of memorabilia: provenance (origin), age, condition and scarcity, according to Mahn Miller.

A paper flier from the 1970s advertising a Prince appearance could have more value than a more durable artifact, she noted, “because that’s the kind of thing people tend to crumple up and throw away.”

If you want to own something relating to the life or career of Prince, be careful, do your research and try to make certain that you are buying from a reliable source, she cautioned. “Ask a lot of questions. It’s on them [the seller] to prove to you that what they have is genuine.” If the seller claims that an item was worn or played by Prince, ask for or look for a photo showing that the musician had contact with the item.

Fan forums can be a good source of information, she said. “They know better than anyone what’s authentic. … You can also research people online. Companies that sell fake memorabilia get sniffed out and develop a reputation.”

The longer-term market for Prince memorabilia remains to be seen. “We won’t know for another year,” she said.

A few deceased celebrities, such as Elvis Presley and Marilyn Monroe, have stayed in consistently high demand. The market for Michael Jackson memorabilia after his sudden death followed a different arc. “It experienced a tremendous peak right away, stayed high for a few years, and has gone back down,” she said.

Scarcity may keep the market robust for Prince memorabilia. “The Prince market was already strong,” said Mahn Miller. “In the rush to get property to market, you run the risk of inundating the market, but I don’t see that happening with Prince. There’s not enough property, and there’s a lot of interest. He died so young. It’s not like a Frank Sinatra who had a longer time to amass things. And Prince was a private person. Michael Jackson signed more autographs.”

Before Prince’s death, the priciest piece of Prince-ly memorabilia was the handwritten lyrics for “Purple Rain,” which sold for $70,000 in 2010. Prince guitars have sold for up to $30,000, Prince clothing for $2,500 to $5,000, and signed documents for $600 to $1,000, she said.

Bottom line: Buy something only because you value it personally, not because you’re hoping it will appreciate substantially in monetary value. “The most important thing is to be sure to buy a piece you love,” said Mahn Miller. “Buy a piece you love, and it will always have value for you.”

And approach any potential purchase with a grain of skepticism.

“If it looks to be too good to be true, it probably is,” Mahn Miller said. “If someone is trying to sell a Prince guitar for $300, it probably isn’t a Prince guitar.”