But it is not for the prestige of winning, but for doing it in the incomparable atmosphere of such contests as the Royal Welsh Show at Builth Wells, and the Corwen Shears - Cardiff Arms or National Stadium gone country, it has been said.
"It's unbelievable," he said. "You never get that atmosphere anywhere else in the world."
It is likely that this year will be like none before it, with Coster only available for the first three tests of the tour - against Scotland, Ulster and England - legendary Kiwi shearer David Fagan will come out of a brief retirement to shear the next test against England, and then the full series in Wales, where the Welsh shearing fraternity place him on a pedestal alongside a fellow Te Kuiti legend, former All Black Sir Colin Meads.
In New Zealand earlier this year, Welsh team manager Bill Jones "prayed" Fagan would make one final venture through the valleys, and said: "In Wales, David Fagan is like God."
The 53-year-old Fagan's first event in the UK will be at the Great Yorkshire Show, where he won his 600th Open final five years ago. He's won 40 finals since then, and more than 150 of his wins have been in the UK.
King, whose first Northern Hemisphere win was at Canada's Calgary Stampede in 2006 and who later won a lambshearing final at Glenarm Castle, Northern Ireland, said: "It's going to be a real honour to shear with David, on his last blast through Wales."
Having announced during the summer his intention to retire at the end of the New Zealand season, Fagan won a right to a place in the team by winning the NZ Shears Circuit final, but had said he expected to relinquish the place on the tour.
"He wasn't going to come," said King, "but even that night in Te Kuiti you could see that twinkle in his eye".
Loaded up with a couple of hand-pieces, about 30 combs (some from the 2006 trip), and about 50 cutters, and kit sponsored by newly named CP Wool (formerly Elders) and Hawke's Bay enterprise Primary Wool, Fagan doesn't expect anything easy, saying: "They've come to New Zealand and learnt our way. They're all quite handy, those Welsh boys."
King and Coster, travelling with manager Ronnie King - a "Gisborne boy, Northern Hawke's Bay farmer" now farming at Tiraumea in Wairarapa - will have practice sheep to shear on Friday, before launching into the competition the next day.
King will return home to pack up house and look for another, having just confirmed a sale this week, and says he is looking for something "lifestyle" and doesn't expect to be shearing.
Like others, he does expect to be lured, during the summer, into the chance of winning a place in the New Zealand team for the next World Championships in Christchurch in 2017.
Itinerary: Saturday, v Scotland, at Lochearnhead; July 10, v Ulster, at Shane's Castle, Northern Ireland; July 11, v England, at Cockermouth; July 15, v England, at Great Yorkshire Show; July 17, v Wales, at Cothi; July 18, v Wales, at Lampeter; July 23 v Wales, at Royal Welsh Show; July 25, v Wales, at Corwen.
