Never let it be thought that the Millionaires Factory folk would be too proud to bend over to pick up a silver coin from the street.

Making a $1.2 billion profit selling out of Rome Airport hasn’t prevented Macquarie Airports stooping to gouge an extra 50 cents from everyone catching a taxi at Sydney Airport, lifting the charge to $2.50. That translates into an extra $1.5 million a year profit for MAP, according to the SMH. Give a robber baron a monopoly and he’ll … well, that’s why they were called “robber” barons.

Macquarie’s exploitation of its Sydney Airport monopoly is ruthless. Try to avoid the taxi charge by driving to the airport and you’ll find parking at the domestic terminals now costs $42 a day. So, go away overnight and the parking bill will be $84. Being dropped by a hire car or a minibus? There are $3 and $3.50 fees for that.

And where Macquarie goes, the other airports won’t be far behind. All those 50 cent pieces just waiting to be picked up. The only mystery is why they didn’t jump straight to $3.

But not everyone makes money exploiting what should be infrastructure monopolies. The AFR broke the story this morning that the receivers have found a buyer for Sydney’s ill-fated Cross-City Tunnel at a price that means the original investors will recoup just 10 to 20 cents in the dollar.

That’s better than many expected, thanks to a consortium led by ABN Amro and Leighton Holdings being prepared to pay $700 million — only $300 million less than it cost to build.

Which leaves one wondering how much upside the new owners might think there is in suing the NSW Government over re-opening roads whose closure was meant to funnel victims into the toll-road.

Leighton’s involvement is a little curious. The firm routinely takes equity in projects it helps build, but this is something else – another sign that the fundamental nature of the construction giant is changing. Leighton thinks so little of the investment that, as of our deadline, it hadn’t bothered to notify the stock exchange. But it did file a release on picking up a $116 million rail project.