Their apartment fetched the biggest sale price of the four apartments that were auctioned at Dux House in Albert Park, selling for $636,000 over the reserve, which was set at $1,834,000.

The pair won an additional $100,00 for making the biggest profit.

It was a fairytale ending for the Melbourne couple - a milliner and a chimney sweep - who had the least renovating experience of the four teams. Twins Lysandra and Alisa Fraser won The Block Sky High last year, Brad Cranfield and Dale Vine were past contestants, and fellow first-timers Kyal and Kara Demmrich have renovated a house together.

"We had never designed a room together," said O'Donnell after their win. "We didn't know - with no background - if anything we did was of value, and now we know [it was]."

Buyers' advocate Frank Valentic bought the winning property on behalf of a young Melbourne couple. "They were quite emotional, they want to be in Albert Park, they've missed out on quite a few properties in the area, and to get a property like that to live in in Albert Park is probably never going to happen again," he said.

The auction, which screened on Channel Nine on Wednesday night, was a contained affair, with around a dozen people bidding on each loft-style apartment. Mr Valentic suspected that auction order might have had some bearing on the results.

The sale prices on the night increased with each successive auction, and Ford and O'Donnell's apartment was the last to go under the hammer.

"I think with the first one you sort of see what happens and see how you go," Mr Valentic said. "I think it definitely compromised Brad and Dale's position coming off first."

On Tuesday night, Ford and O'Donnell looked increasingly nervous as the other apartments sold well over their reserves.

"We just want to sell it!" said Ford, ahead of their auction. "When we applied for The Block, we just wanted to get on The Block, and we stand by that today, as cheesy as it sounds, that made us winners.

"If we just sold our house, that would be such a win, because it was the experience that we wanted."

The first thing they would do with their prize money, they said, was throw a "massive party" for their tradies. Ford and O'Donnell's builder, Luke Shand, was also a first-timer on the show. He said that the way Ford and O'Donnell were portrayed on the show wasn't "really accurate".

O'Donnell, in particular, was described as "lazy" by the other couples.

"I think he was more just inexperienced, he'd never done any sort of renovation work before, he got thrown straight in the deep end, he was like, 'I have no idea what I'm doing', I would have been the same," Mr Shand said.

"It's like asking me to be a hairdresser, I'd be terrible."

If a property sells above its reserve, the four couples - who each renovated a three-bedroom and three-bathroom apartment over nine weeks late last year - get to keep the difference.

All couples this year went home with over $500,000. Opinion was divided on the price of the reserves. "I think the producers have always been fair with their reserves, they've given these guys who have worked so hard the chance to be rewarded for their efforts," said Ford and O'Donnell's auctioneer, David Wood.

"If they didn't make money they wouldn't go on the show."

Towards the end of the gruelling shoot, Ford and O'Donnell's relationship looked uncertain, but on auction night on Tuesday the couple said there was no truth to rumours they had broken up.

"Every relationship goes through ups and downs and you have disagreements, ours just happened to be on national TV, that's nothing new to The Block," Ford said. "If you come out the other side of this, how could you not be strengthened?"

Filming has already begun on series nine of The Block, screening later this year.

Apartment 1
Couple: Chantelle Ford and Steve O'Donnell
Sold for: $2.47 million
Reserve: $1.834 million
Signature feature: Their expansive living and dining area, a hit with the show's judges

Apartment 2
Couple: Kyal and Kara Demmrich
Sold for: $2.44 million
Reserve: $1.872,750 million
Signature feature: Boasts the northernmost position in the block, and an $8,000 bathtub

Apartment 3
Alisa and Lysandra Fraser
Sold for: $2.375 million
Reserve: $1.759 million
Signature feature: The kitchen's striking high ceiling void, providing ample natural light

Apartment 4
Brad Cranfield and Dale Vine
Sold for $2.31 million
Reserve: $1.802,750 million
Signature feature: The bathtub in the master bedroom