There are several good reasons why this card has
38 days left on its playability in extended.
First, it tutors. Granted, it's only for an
artifact, and you have to sacrifice an artifact,
but how about exchanging an artifact land for a
Platinum Angel? Or a spent Tangle Wire for a
Second, this is mana acceleration. You don't have
to pay the mana cost of the artifact to bring it
into play - it comes into play free. So you likely
save 4+ mana by using this card.
Third, this allows to to get away with only having
one of certain high casting cost artifacts in your
deck, and thus, lessens the chance of you drawing
All this will lead up to this being the first card
on the banning announcement, coming next Monday.
In limited, there's not enough artifacts in Urza
Block to make this worthwile, or to be able to pay
the additional cost.