Cost efficiency means jack shit if you can't get the item online to be relevant when you need it to be. There are a ton of issues with the item, mainly that it doesn't offer stats that most tanks need to get their kits rolling, so that immediately makes it a second purchase if that. The next issues is that it's only relevant against turrets, and by the time you're finishing your second item, you've probably busted a few turrets already, and the more turrets that go down, the less and less relevant the item becomes. If it had Demolish as a passive ability, it would become an immediate pick for a lot of people, but Riot seems to have forgotten the item exists. It should really be removed at this point, it's been dredge in the gutters for years.