Oracle's Extract Nerf Needs to happen

I hate getting killed by teemo, shaco, akali, and others as much as anyone but what I hate more is being those characters in ARAM. A 300 gold item can be bought by every member of the team, has a radius of half the width of the bridge, can be bought multiple times and lasts for minutes is available. It destroys everything about shaco's and teemo's kit in particular. Just one person buying this item ruins any chance of those characters being relevant. Make it more expensive, only let one person buy it, make the radius smaller, make it last less time but good grief it ruins invisible assassin's kits.