I purchased a pair locally for £10 too
I wonder if you can use this with the 10% off voucher the AA App is currently running.
They were labelled as £10 in my local last weekend...
They had the other type, with a bar that looks like it's a lever rather then slides out to adjust 3 tonne for £20 (£30 online) and 2 tonne for £15 (£23.99 online) If I get chance I'll pop back tomorrow to see if they removed the tags or still priced this low. Was Mersey Retail Park
It might very be be a point of sale/ticket error, but it's worth having a look if you're nearby a Halfords and in the market for a set.