For example, 25 per cent of products listed in PriceSpy's computers and accessories category saw a price hike on Black Friday. At the same time, 33 per cent of products in this category saw a price drop.
Matinvesi-Bassett said the research shows shoppers need to dig deeper and look at how much the item they are looking to buy has been sold historically to see if a Black Friday -or any - discount is true.
PriceSpy research showed 38 per cent of products saw a price drop on Black Friday 2021, and 19 per cent dropped by at least 10 per cent or more, offering an average saving of -21 per cent.
It said the biggest Black Friday savings this year came from fitness watches, PS5 games and electric toothbrushes, which saw price index changes of between -18 to -29 per cent according to its price index data.
"Whilst sales days like Black Friday can help boost sales opportunities for retailers who have had a very difficult time these last few years, to really earn the trust of shoppers who are being sold the dream of getting a real bargain, fake sales need to be avoided and pricing strategies need to be more transparent," said Matinvesi-Bassett.