Don't have any particular ideas but tank items for lowering de-buff and cc times would be a good addition for the later game to mitigate the need to win the one team fight late-game for a guaranteed win, which will put more emphasis on focusing objectives over kills/early lane swaps/ganks
There's a few that do but I don't think we should be debating on selling cheaper items later in the game to grab better ones, at the very least making all tier one items upgrade to tier 3 or 4 would help the flow of the buying process.