Okay, it kinda seriously bugged me that Elvira found all those items xD... with a giant leaf to carry them. I mean there's probably giant leaves in the rain-forest and stuff, but so far I haven't really seen any giant leaves in the Pokémon episodes.
Considering most berries in Pokémon are the size of a grown persons hand... I think I shall limit everyone to like 3 held items xD.
And there's unlikely we would find that many items in such a short while... perhaps if everyone spent an entire day looking for them... otherwise I think its bit of a... aceaus mod even with a character that's good at finding stuff. I'n the show they kinda make berries seem common in some places only. Like berry trees and stuff... but its unlikely you would find several of 'Every' kind.
Like stated in the post, a 'Life time supply' is overkill. xD... not that I mean for us to spend long whiles looking for healing items... but it kinda defeats the point.