Like always, my choices for the list are subjective
* Cards like "Tour Guide From the Underworld" , "Rescue Hedgehog", and the currently 2-card starter-like "Goblin Rider" have almost no search methods, so they have been omitted
I was able to open about 20 packs the first day for free because of all of these methods together
Black core is typically more expensive than blue core
As it stands, they are 1 mana off Karn, the Great Creator + Ensnaring Bridge if they topdeck Karn, the Great Creator in their draw step
However, for your combat damage to get through, you will need some protection from your opponents after they have either saved up the mana to blow away some of your Humans or kept some of their poor creatures untapped to block you (even if your creatures can't die because of Goldbug, Humanity's Ally )