(CNN) -- A gift shop set to open to the public on Wednesday at the 9/11 Memorial Museum has sparked controversy among some victims' families.
Among the items sold: hats emblazoned with the FDNY symbol, search and rescue stuffed-dog animals and a slew of books relating to the attack and building of the memorial.
Organizers of the museum acknowledge that the cost of operation, about $65 million yearly, will require the support of revenue generated from the gift shop, and the museum's admission fees, with $24 for an adult. It will also help maintain the free admission to the museum's outside memorial.
"To provide an opportunity to buy a keepsake and have those proceeds support this open and free memorial is something I would do seven days a week," said Joe Daniels, president of the National September 11 Memorial Museum.
He says the gift shop is situated in a "respectful space" in the museum and notes that the No. 1 sellers so far are the DVDs and books they sell that educate the public about the history behind the events of September 11.
But some in the 9/11 community are bristling at the idea of monetizing their families' final resting places.
"I think it's a revenue-generating tourist attraction," Jim Riches said of the museum. Riches, who is retired from the New York City Fire Department, lost his son, a firefighter, in the attacks.
"Basically, they're making money off of my son's dead body. I think that's disgusting," Riches said.
Also at issue? The roughly 8,000 unidentified human remains that will be housed in the museum. Riches likens the accompanying admission fee to "charging people to get into a cemetery."
"Let's bring the remains up to a respectable location ... above ground with an eternal light. Everybody can visit them, you won't pay $24 to get in there," he said.
But Lee Ielpi, a member of the museum's board of directors who lost his son Jonathan, a firefighter, in the attack, hopes that the revenue generated will help maintain the museum.
"We have an obligation to society ... 20 years from now, we need to make sure the people that step foot on this plaza know where they're stepping and when they go into the entrance and go into the museum, they need to know what they're going to see there," he said.