When you cast it for free from your opening hand, it costs 3 mana to equip at sorcery speed
The land here is a reprint, while the three new creatures are good
Giving a -1 toughness debuff (and thus killing!) your own creatures is actually a worthy sacrifice in this case, letting Skullclamp draw you two cards for the best rate this side of Ancestral Recall
I've seen people just decide not to cast their second Swords to Plowshares because they had one in the graveyard already
There are way more than just the original 10 guildgates now, so options are plentiful, and there are tons of good land tutors available like Circuitous Route, Scapeshift, and Crop Rotation
But for the rest, all but the most obsessive optimisers can easily forgo the hip-pocket hit from these cards and grab their value-brand replacements