@FanOfMostEverything  
Different effects. Land-fetching means grabbing a land from your deck and putting it in your hand. Ramping allows you to put more than one land on the battlefield in a turn. Compare Attune with the Aether with something like Explosive Vegetation.

@Background Pony #8568  

I thought land-fetching was ramping. Also, Cultivate says hi.

This is objectively the best fetch land card, ever (not) printed.
 
Think of it this way, Attune with the Aether is played in lots of standard decks. This is SIGNIFICANTLY more powerful. I highly doubt Wizards will ever print a card that lets you fetch a land and ramp at the same time. It would need some significant downside. Maybe it should cost 2 mana and say ‘if you control exactly two lands’, or say ‘you take 4 damage’ or ‘your lands don’t untap next turn’.

This is really powerful.

Looking at green spells with “search your library for a basic land” spells at G, commons seem to only go to hand, and rares directly to the battlefield. There are no uncommons, and none with a condition like this, so that might be the design space.
 
That said, if ever this came about, it’d probably only let you play the basic land you found; i.e., “If you control exactly one land, you may put that card onto the battlefield instead.”
 
I’m now trying to figure out how to make your description work. ^_^

@GeoPony
 
I was going to say “or even rare” as well, but I’m not the greatest judge of the difference between rares and uncommons. I guess this could be more useful in the uncommons to help with mana fixing, and there’s been busted stuff put at uncommon before.
 
But as a common? I’m getting a Treasure Cruise vibe. And I don’t think it would even be balanced in limited formats. Those would have to be designed around the power level of this one card.

@Psyco Josho  

 
uncommon or even rare. Since you don’t have to put that basic land you searched for in as your second land, almost seems like it should cause the second one to come in tapped.

@Psyco Josho  
Possibly. Rarity’s the one area where I’m flying completely blind.

A bit strong for a common. Maybe an uncommon.

@I Was Never Here  
It works for a multicolor green deck too. Just pick a different basic land for the last one you play.

@FrostPon3  
Yea, two land turn one is nice.
 
Then if you have two of them in your hand you can even pull another land out of your deck right away. It would be great for a pure green deck.

This card would be worth a lot for just 1 Green. :O