Changing Sightstone, Support items revamp.
A must have item for every support. The issue being supps are the players that are bound to have the least gold and SightStone's negligible stats.
So a couple of options:
Make with supp items what they did to Jungle items, so having the option to upgrade 
, 
and 
will give the item the ability of laying wards or distinct changes to exhaust or heal the same way jungling items change smite, limiting the use of the item to those who have one of those.
Example 1:
Upgrading to 
allows to place 2 
that refill upon visiting the shop.
Example 2:
You get different possible upgrades for 
.
1- increase the movement speed of allied champions towards the enemy champion affected by your 
.
2- increase the duration of .
3- drains mana from the target.
4- increase healed amount by 
5- restores a bit of mana
Example 3:
This would be the less extreme change.
1- 
gives 10% cooldown reduction
2- gives 50% mana regen.
Example 4:
Add more Support items that are effective and not very expensive, allowing support to reach an equivalent of "full build" and keep up with the team without being a second class citizen.
These items would have to be exclusive for supps (like jg items are to jg) in order for them to not be abused by the rest of the players.
Things of the sort of some kind of equivalent to regular items like 
but that cost slightly less.
