A day after Michael Bloomberg loaned the in-progress 9/11 Museum $15 million of his own money, it turns out future visitors will help pay him back. “We’re still in the process of considering how much, but it will be in the range of $20 to $25,” a spokesman for the memorial told the Daily News today. “It will be a set fee,” not a recommended donation, although we couldn’t really imagine people getting cheap in this case. Still, not everyone is pleased with the decision: “It’s ridiculous,” said former FDNY Deputy Chief Jim Riches, whose son died in the attack. “We asked for a memorial and they’ve turned this into a P.T. Barnum production. These people are trying to make money off the worst day in American history.” Victims’ families, of course, will not be required to pay.