Half of Black Friday deals were actually cheaper before and after the event, a watchdog has found. The consumer group, Which? warned shoppers to “do your research” after it found just 8 per cent of offers were exclusive to the day, while four in 10 could be picked up cheaper after the event and one in 10 items cost less in the months before. Which? tracked 178 deals on 20 popular gadgets and appliances at Amazon, AO, Argos, Currys and John Lewis every day for three months before and two months after Black Friday last year. t found that only 90 out of the 178 deals were cheapest on Black Friday. AO and Currys may also have broken advertising rules after Which? found “numerous” examples of offers that appeared to exaggerate the apparent discount by using an artificially high “was” price. Rules say the “was” price should be the most recent price the item was sold at, for at least 28 consecutive days.