The Block: Mark Richardson reveals fourth and final apartment has sold for $1.6 million

Mark Richardson has revealed that the fourth and final apartment from The Block NZ: Firehouse has sold. 

Contestants Sophia and Mikaere's property failed to meet reserve at Sunday's live auction, being passed in for negotiation.

But on Thursday's episode of The Project, The Block NZ host Mark Richardson revealed the couple's property has finally been snatched up, going unconditional for $1.6 million - meaning all four properties have finally been sold. 

However, $1.6 million is still "fractionally below reserve," Richardson told his co-hosts.

"Sophia and Mikaere won't be walking away with profit."

Lisa and Ribz secured The Block win by a landslide as the only team to make a profit at Sunday's auction, walking away with $50,000 plus the $100,000 cash prize.

Sophia and Mikaere's home was listed on TradeMe following the "disappointing" auction. Bidding for their penthouse property stopped at $1,455,000.

The listing boasted the "outstanding two bedroom penthouse" as the "ultimate prize".

"The generous master suite is a private sanctuary designed for unwinding in style, with an elegant ensuite and walk-in robe, not to mention access to your own terrace for morning coffees," the description said on TradeMe.

"The kids' bedroom works equally well as a home office or guest bedroom and enjoys its own special views to the city. Skylights invite the light to pour into the carefully crafted family bathroom.

"With your own car park, every modern comfort and situated on the doorstep to some of the best cafes, bars and restaurants, The Block NZ: Firehouse's Sophia and Mikaere have crafted a luxurious apartment for any age or stage."

The luxury apartment also has stunning, expansive views of Eden Park, the surrounding Auckland volcanoes and the twinkling lights of the city and Sky Tower.

Richardson suspects selling the four apartments on the same night may have depressed their market value.

"It's not your ideal, but it's a TV show...  I would have liked to have seen the others make more money, but it didn't happen. When you go into that auction room, you're at the mercy of the market - and we saw where it's at," he said.

Economist Cameron Bagrie said there were "no surprises at all" about Sunday night's episode.

"We've known for a long time now Auckland's been the most sluggish, the weakest part of New Zealand. Why? ... Because it's the most damned expensive if you strip out Queenstown. Auckland still trades at a house price to income ratio of up close to nine.

"Generally speaking, the cheaper places around Auckland - anything south of the median sale price of $850,000 - is still firing out the door.

"But stuff in excess of $1 million, $2 million, that sort of stuff is not what you call hot. We're struggling to sell it, and we saw that on television [on Sunday]."