Allow the game setup toggle of randomly selected Items available for purchase, at all shops. Items would be chosen completely at random from an Item archive/database. Different Items might be in the shops therefore each time you play.
Sorry if that wasn`t too clear in my original post.
Oh okay, now I understand what you're saying. So you make which items are available randomized, so every game the selection is different.
I like that idea, although I don't think it should be a toggled option. I think different items should be available on different maps (selection can be catered to the map for balance purposes etc.). The only problem is currently there aren't nearly enough items available for varying selections on different maps to be noticeable. Once they add more items with characteristics that are different enough to be noticeable, this idea would be great to implement.
I think the toggled (non-standard) option would be to allow all items. For competitive play certain items should be limited to certain maps. That'll force players to use different item builds in different situations. It'll also allow more interesting items to be made, some even designed specifically for one map.
Just having them be randomized and non map-specific could still be interesting, too.