Theres obviously a heck of a lot of profit margin in there by the time it gets to £30, but like probably all manufacturing set-ups, they will have have a manufacturing system set-up to deliver parts straight to a production facility in quantities to match a pre-planned batch quantity. It probably costs just as much to seperate, package, ship & handle a single item as it does a whole finished assembly, because they are not set-up with an inventory to handle single items through to retail. You would probably be amazed how small the raw manufacturing cost of that lever blade is, but by the time you’ve factored in material, handling & purchasing burdens your £0.50 lever blade probably becomes something like £5.
Or something like that. 😐