Look for cards like: : Not technically a land, more a mana rock that produces 2 green mana as well as buffing each non-token creature you play, and giving you a draw to replace it with
Thats less than a dollar per pack, and will give you a good start on the new cards you might need for upcoming Standard, and all those packs you open will also give you a decent number of rare and mythic wildcards
But outside of that, the madness for three mana, and one fewer Red helps to make the cost more manageable, while the effect is no less face-smashingly real
Powerwise I'm aiming between Arrogant Wurm and Shadowgrange Archfiend who was making players cry in conjunction with Lion's Eye Diamond and Hogaak, Arisen Necropolis and was subsequently removed from the cube
The creature helps you ramp with your creatures, while the backside helps to cheat out creatures and planeswalkers from your library for free