This "bug" happens on my PS3 version and now my PC version.

This is about the Merchant perk from Speech skill line, the one allowing you to sell anything to any trader.
I understand this perk also allows you to purchase items from vendor's personal inventory, items normal wouldn't appear on the list. However it seems I can ONLY purchase items from vendor's personal inventory.

For example, Adrienne from Whiterun no longer sells tons of ingots and ore; Acadia from Whiterun no longer sells tons of ingredients; Lucan from Riverwood no longer sells those basic spell books.
Instead, they sell things like one iron dagger, one lockpick, a few sorts of food, etc.

I can't be the only one with this problem, and can't be the only one who feel this way is doing more harm than benefit.
Any help?