"I didn't go out to the market place, so it's just circumstances. It just gets to the point where you get old and you've got to make a decision which you really don't want to make."
When Wallace first spied 79 Ormiston Rd at the Te Irirangi Drive intersection, it was so far out in the country - "you have to remember, it was all farmland then, there were cows all around" - that it was the best place to establish a lawn business, Turf Grass Specialists, and grow lengths of the newly popular ready-lawn.
"So I was just growing the grass on it."
As the city inched closer, they saw leisure opportunities, so the family bought a neighbouring golf driving range and established the Firmount Golf Park with Cafe Bosporus, a Golf Warehouse, mini-putt and driving range, buying the Telecom Shed which was a temporary America's Cup Viaduct Harbour building.
Then, giant businesses shifted into the area: Lion Breweries left Newmarket and moved its brewery and offices to 55 Ormiston Rd, near the huge new Farmers Support Centre, and Wallace realised prices were rising but was more focused on the golfing business and cafe rather than escalating valuations.
"So that's why I'm not the most excited person when it comes to bags full of money because when you're a practical sort of person, it's the creative aspect of what I've done.
"I personally don't get excited about it because I wanted to be successful in my businesses."
The Wallaces have given back to their community: in 2007, the couple were honoured at the Westpac Manukau Business Excellence Awards for supporting The First Tee of New Zealand, an international children's charity.
Now, one of Wallace's biggest concerns is the fate of extensive, mature gardens with enormous palms on the site: he does not want to give them away but nor does he want to see them destroyed when the land is redeveloped. So he is open to offers and people could get in touch with Firmount Golf Park.
"It's like the regional botanical gardens here. The orchids are all in flower," he said from the cafe.
As for rapidly rising prices, Wallace remains a sceptic and is emphatic that he never went into the business of real estate.
That, for him, was simply a byproduct of what he and his family set out to do, establishing a thriving business on a big site which when they bought was well on the city's outskirts.