Give Ruby Sightsone a buff??
is an item which even support wont often buy it.
Reason:
- You need to spend 800 for bonus hp and 1 more ward charge, support only buy it when he have full item.
2.Some support will not even buy it because they need to make sure they have enough money for

Nowadays, support need to leave 1 slot late game to have
.They dont have chance to have 6 item which reduce their survivability in the teamfight.
As a result, I suggest the following changes:
1. increase the maximum charge of wards to 6
2.give a unique passive: "upgrading" When u place a ward by your sightstone. It will show an small aura for 5 second. If the same guy put a ward by sightstone again in the aura. The first ward will disappear.Then the second ward will take 3 second to transform into a pink .
During transformation ,the ward will give the vision of a normal green ward.The ward which can be destroyed is visible and have 5 hp.
P.s:The transformation time is to prevent someone need to build hp to buy this for countering stealth champ hard.
3.In return to the buff,increase the upgrade cost to 1000g from 800
In conclusion, I think this can give support another choice during mid -late game for better map controll rather than an item which is luxury.
(Sorry for my bad English)