"We were on a family vacation at a resort in Bali, but we really liked Bondi and we always liked Ben Buckler," said Lavecky, CEO and co-founder of global blockchain company Canvas.

"But we pulled the trigger and got it the night before the auction.

"And when we came back to settle it, it was everything we dreamed it would be."

Their detached five-bedroom, three-bathroom and double garage home at 177 Hastings Road has spectacular beach views and a flat, child-friendly garden on a large 480-square-meter lot.

At the time they bought the home, David and his brother Daniel had just sold their money platform, Pure Commerce, to NASDAQ-listed fintech company Euronet Worldwide.

But now the brothers have their own new business, providing infrastructure support for financial digitization, while their two children, Iliana, 11, and Elisa, 7, are growing up.

So the couple is looking for a "change" near Double Bay, Darling Point or Point Piper, where their home is being sold by Raine and Horne Double Bay/Bondi Beach principal Ric Serrao.

We're currently interested in the $20.5 million level and we're looking to build on that," Serrao said.

A local couple looking to upgrade and an offshore buyer are both interested.

For Lavecky and his family, he says parting ways with Ben Buckler's property was "a tough decision.

"Living by the beach has been great," he says.

When they moved in, they focused on improving their backyard for their children.

We really wanted them to have a good outdoor experience in keeping with Carina's Danish heritage", says Lavecky.

The yard has a nature trail, climbing wall, swings, slides and cubbies.

"The kids really like it and spend a lot of time in the backyard," he says.

And for mom and dad, the favorite part of the house is the parents; the retreat.

"We love the view from the beach, especially on days when the water is super still - it's like a lake," David says.

"Have a glass of wine, relax and watch the sunset ...... It's really nice that the kids can run around downstairs and upstairs we can have peace of mind."

Afterpay's Nick Molnar and his wife Gabrielle, Australia's youngest billionaire at 33, own three blocks on the street where they paid $18.5 million for a block of three units next door to the house they bought for $27 million two years ago.

PropTrack puts the median home price in North Bundy at $4.35 million last year.