However, it is obvious some retailers will use the change in GST from 12.5% to 15%, a rise of 2.2%, to increase their prices much more in an attempt to recover lost margins.
Reserve Bank governor Alan Bollard has warned utility companies and retailers not to use the GST rise for price-gouging.
Otago Chamber of Commerce chief executive John Christie had noticed some businesses, including retailers, were advertising prices plus GST rather than GST inclusive.
"Retailing is traditionally the total price, not the price plus GST. There is a lot of variation out there."
Some retailers had already increased some prices but whether prices went up or stayed the same depended on how competitive the sector was.
Mr Christie predicted a lot of rounding up of prices would take place, but not all of them on October 1.
"We will see a lot of changes a few weeks after the implementation date. This could take weeks, or even months, before businesses fully adjust their prices," he said.
The chamber was finalising a survey to members regarding pricing intentions.
Deloitte Dunedin tax partner Peter Truman was guarded in his comments when asked by the Otago Daily Times how he thought retailers would respond to the rise a week on Friday.
This writer bought an item at a national chain last weekend with a marked price of $39.99. When it was rung up by the shop assistant, the price on the till display showed $49.99. Asked if the price was correct, the assistant said the higher price was the new price with the increased GST.
When it was pointed out that the new price would be less than $41 ($40.87), the assistant said the prices had been programmed in and that he had pushed the wrong button.
Mr Truman said while some retailers would use the GST rise to try to push up prices higher than 2.22% to reclaim some lost margins, he believed most would be careful.
"I would have thought the retail environment was sufficiently tight and competitive for retailers to not want to increase prices above the rise in GST."
Mr Truman said it appeared the average price of a cup of coffee was rising from $3.50 to $4, as cafe owners used GST to review margins lost from previous price increases in milk and coffee.
"A lot of retail product is sold at price points and therefore it is not a simple case of increasing the price by 2.22%."
For example, if an item sells for $9.99 now, it is unlikely the price will be increased to $10.21 on October 1," he said.
If prices were going to increase, businesses needed to consider how they were going to re-price stock, Mr Truman said.
WHK tax principal Jarod Chisholm said price increases were a difficult issue for many small business owners who did not have the flexibility to move prices by too much.
He cited the liquor industry as a prime example where small liquor store owners were pricing against supermarket owners who were prepared to sell some lines at a loss in an effort to attract customers.
Mr Chisholm predicted that some retail prices would jump by more than the rate of the GST rise where retailers could see an opportunity.
However, other prices would not rise at all.
"There are products out there that people won't pay more for."
Included in those products would be land developments, he said.
If a developer was advertising a section this week at $200,000, it was unlikely its price would rise to $204,000 at the end of next week.
It would mean the developer would be making less money in the short term.
• How it works
To find out what an item will cost when GST rises from 12.5% to 15% on October 1, divide the price now by 112.5 and multiply the result by 115. An item costing $9.99 now will theoretically cost $10.21 on October 1.
