Packaging tactics run the risk of misleading shoppers about products and deals, according to consumer group Which?.
The watchdog highlighted one case in which a Lynx gift set sold for £6.50 contained a deodorant that normally costs £3 and a £2 shower gel.
Manufacturer Unilever told Which? that the cost of making gift packs was much higher and retailers set the price.
Which? also highlighted "misleading" product names and copycats.
It said it found several examples of fruit drinks that had the main ingredient missing from the name. One cherry and strawberry smoothie contained 18% of those fruits, but higher levels of, cheaper, apples and grapes.
Manufacturers said that they named products based on the main flavours.
Other criticisms from Which? included examples of supermarket own-brand products mimicking the look and feel of well-known brands.
"We have found packaging tactics across the supermarkets that run the risk of misleading customers. Supermarkets and manufacturers need to play fair to avoid confusing consumers," said Which? editor Richard Headland.
"We are campaigning for simple food pricing to make it easy for consumers to compare products and find the best deal."