Consumer NZ's latest specials survey found items can be on "special" so often that some products are promoted as discounted almost every week.
The independent watchdog tracked prices for items across four "big box" retail stores: Briscoes, Farmers, Harvey Norman and Noel Leeming.
Consumer NZ said 27 out of 31 products surveyed over 13 weeks were on sale at least four times - but some as much as every week.
"So when is a 'special' really a special? If something's on sale for longer than it is at its regular retail price, we'd argue that's the price of the item," said Consumer NZ head of content Caitlin Cherry.
At Harvey Norman, six of the seven products surveyed were promoted as "specials" almost every week. Consumer NZ said the retailer declined to comment when asked for an explanation.
Cherry said retailers were continuing to engage in "misleading and confusing pricing strategies" to try and get customers to spend more.
"Slogans like 'price matched' and 'huge deal' make things even more confusing. Consumers can't tell what a true sale is."
She said stores should be offering genuine deals.
The watchdog also tracked eight items at Briscoes - all of which were regularly on sale. Briscoes said its compliance with the Fair Trading Act was ensured by "a robust internal audit process".
Newshub has contacted the four retailers surveyed for a response.
