Actually, The cost saving isn't really adding up to much.
When you see something like this https://www.ebay.co.uk/itm/CLASSIC-TRIUMPH-GT6-MK1-PAIR-LUCAS-Wiper-Blades-11-INCH-GWB223-5-8mm/352588693840?epid=2091889394&hash=item5217ec8150:g:IC8AAOSwYPNcWKLw