Which? sniff out the Black Friday prices of 35 of the most popular technology, peaceful and personal care products sold by Currys PC World, Argos and Amazon.
They establish that 60 per cent of the deals could have been create at other times during the year, or for a cheaper price.
A Neff Skid and Hide Oven at Currys for £494.99 for Black Friday was cheaper for at dwarf 113 other days of the year and £45 less expensive hardly three weeks later, the watchdog found.
And an Oral B electric toothbrush from Amazon was advertised as “keep 26 per cent: was £40.49, now £29.99”.
However it was £5 cheaper on at least two lifetimes in July.
UK shoppers are expected to spend £2.6billion this Friday, according to intimations by VoucherCodes and the Centre for Retail Research.
Currys said: “Last year, Currys PC Humanity alone featured around 4,000 products reduced as part of our Coal-black Friday campaign.
“The fact that some of these were then truncate further in the months after that period is simply us continuing to come forward our customers great value throughout the year.”