Of course, you want to be attacking as soon as possible, and taking advantage of extra combats with the new creatures you have
Spend this mana only to cast an instant or sorcery spell
Black Uncommons Demonic Tutor $120/$60 Hypnotic Specter $80/$40 Animate Dead $50/$20 Sengir Vampire $40/$20 Black Knight $15/$6 Netting Imp $7/Unlisted Evil Presence $6/Unlisted Sacrifice $6/Unlisted ALL OTHER BLACK UNCOMMONS $5/$1 The top three cards on this are all Cube staples, but Demonic Tutor and Animate Dead are also playable in everything theyre legal in
Does it hurt to suddenly have to pay twice as much as before
The first copy of Risk Factor is usually pretty easy to ignore and you just take the four damage instead of giving the opponent three cards, but with jump-start its usually pretty difficult to take another four damage and still survive the early pressure or other burn spells red decks can put together
There are countless artifacts that give you value when sacrificed, like Myr Retriever and Chromatic Star