Welcome to Melbourne's most expensive park: a one-acre playground to be created in South Melbourne that, thanks to Opposition leader Matthew Guy's rezoning of the Fishermans Bend urban renewal area, will cost taxpayers $14 million more than its owner paid for it.

Planning Minister Richard Wynne said in state parliament on Wednesday that the Andrews government had agreed to pay $19 million to coffee entrepreneur Pitzy Folk for a warehouse set on 4000-square-metres of land that he bought in 2008 for $4.4 million.

The land was then zoned industrial.

But Mr Folk and his neighbours were the recipients of a massive windfall after hundreds of hectares of South Melbourne and Port Melbourne were rezoned overnight by Mr Guy as planning minister in the former Coalition government.