I purposely not mentioned any supplier specifically Peter as all kit suppliers are in it to make a living or to supplement there meager salary from their main job.
So no matter what they do they have to make a profit and sell pens.
To do that they have to have someone buy them. If they are just a few pence cheaper then many will buy them rather than think of the quality of kit they are actually getting.
Having said that, Neil has a footnote says it all.
"There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man's lawful prey. (John Ruskin 1819-1900)"