nerf coin INCOME too riot.
it is too passive and too rewarding. you get more gold then anyone who builds
by just standing in lane. it's not only the mana, its that you get 40 gold per coin with medallion. you often don't even have to upgrade it since there isn't even much of a passive buff. it gives you easily 300+ gold on your opponent's support and it requires less skill to use. you could also nerf the time it stays on the field. right now you basically automatically get your coin due to minion waves coming in before it dissipates.
with a lategame adc.