It can't be cheaper unless there is something different (inferior) about it. Otherwise, why make HP5+?
Films aren't monolithic. Different films have different characteristics, and the various characteristics have different levels of significance for different users in differing usages.
Otherwise why make Hp5+ and Delta 400 and Kentmere 400?
Or for that matter, T-Max 400 and Tri-X 400?
Kentmere 400 is superior to HP5+ if its relative economy and less effective anti-halation and excellent availability better meet someone's needs.
