Mrs Tacon's lawyer, Bill Calver, said yesterday while targeted rates had been used historically in the Hawke's Bay area, in this case the purchase of the domain was not solely for the benefit of the people who were ordered to pay it.
He said the purchase benefited rate payers far wider than the 19 property owners targeted.
"The cost should have been spread over all rate payers, as many people are visitors to the domain," Mr Calver said.
The Hastings District Council claim the purchase of the domain directly benefits the adjacent residents by keeping the land from being bought by developers. If the land had not been bought by the council it would likely have been subdivided and built upon, devaluing properties around it.
Two property valuers had visited the area in the past four years to give advice on what the drop in value would have been.
The council commissioned property valuer Logan Stone, who said the loss would have been substantial. Mr Calver said Mr Stone's report regarding the property valuation was "very convenient for the council" and likely assisted the council in "conjuring up a suggestion" that if the land was not bought by the council the houses surrounding it would lose significant value.
Another property valuer said the drop in value would likely be 10 per cent at the most.
Mr Calver is seeking a declaration of whether the council complied with ratings legislation when applying the targeted rate.
If granted this could mean the council would have to return to the drawing board when it comes to reparation for the purchase of the domain.
A lawyer for Hastings District Council said for Mrs Tacon to be relieved of her share would be "grossly unfair" to the other property owners who had already paid. He said a decision in favour of Mrs Tacon could unravel the whole exercise and could result in the council having to sell the land.
Justice Edwin Wylie reserved his judgement until a later date.
Both Mrs Tacon and Hastings District Council chief executive Ross McLeod said they would not comment on the case until the judgement is released.