Since it takes so many counterspells, removal spells, and planeswalkers to keep the game in check, there often isnt much space in the deck for creatures
If the biggest drawback you're looking at is three in the cost or that it is not legendary and thus cannot be your commander, that's a sign we have a bomb of a vampire
Especially when it comes to dealing with pesky creatures that stand in the way of victory, or annoying permanents that are neutralizing your plans
It will be resilient to plenty of removal spells and it can dominate the battlefield on pure stats if allowed to stick around
I dont think that any of the Commander 2011 legends would break Standard, or Modern
That's $0.18 for Slip on the Ring, $0.35 for Gandalf, Friend of the Shire, $0.19 for Mirror of Galadriel, and $0.20 for Shire Terrace