Initially this was going to be cards $1 and under, but there were too many cool cards just under $3 that I wanted to add. These are cool cheap cards you can get and could really spice up certain decks.
Blue
Aetherplasm - Cheat out a creature via blocking
Iceberg - Enchantment mana storage
Ice Cave - Group fun countering?
Faces of the Past - Tribal Combo
Dreams of the Dead - Reanimate white/black creature for 1U
Shifty Doppelganger - Cheat out a creature at instant speed
Decree of Silence - Oppression + uncounterable counter
Illusionist's Gambit - Take aggro off of you for a turn
Roil Elemental -Landfall steal all the thingies
Annul - Counter that annoying artifact or enchantment. RIP? NO! Sol Ring? NO! etc.
Peregrine Drake - 2/3 flyer for 5 that untaps 5 lands. Great with high tide effects and more.
Tolarian Entrancer - Gain control of all creatures blocking it. Throw a lure on this and steal whole fields.
Confiscate - Steal that planeswalker
Neurok Stealthsuit - Instant speed shroud equipment
AEther Spellbomb - The most useful blue spellbomb
Black
Lim Dul - Reanimate your opponents stuff + regenerate
Choice of Damnations - Fun card
Dawn of the Dead - Reanimate for cheap (works with conjurer's closet/flicker for value
Agent of Erebos - Grave Hate
Body Snatcher - Cheat a creature out
Voidmaw - Remove when creature dies effects
Spreading Plague Helps deal with creatures in certain situations.
Pawn of Ulamog - Turns your dead nontokens into mana tokens
Sadistic Sacrament - BBB - exile 3 cards from an opponents deck, 7BBB exile 15 instead.
Shriveling Rot - For those of us who hate ourselves and everyone else
Death Cloud - For those of us who love group suffering.
Green
Reap and Sow - Land destruction and tutor to play
Pelakka Wurm -Much value creature for cheap on the wallet
Hibernation's End - Tutor to play
Citanul Hierophants - Everything is llanowar elf
Abundance - When you would draw choose if it's gonna be a land or nonland
Pulse of the Tangle - For those of us with tons of mana but not enough creatures
Fangreen Firstborn - For a minor pump per swing
Joiner Adept - Color fixing your lands through use of a stick
Rite of Passage - For those of us who like to abuse certain cards
Tornado Elemental - Punch the flyers then punch the player.
Horned Helm - Pretty awesome equipment. Instant speed attach
Red
Viashino Heretic - Best artifact hate on a stick
Dwarven Miner - Nonbasic land hate on a stick
Shunt - Red redirect
White
Galepowder Mage - Makes something disappear on attack
Planer Guide - Mass flicker
Mystic Barrier - Take some aggro off of you
Leonin Sun Standard -Mass creature pump
Sunscour - Board Wipe
Jotun Grunt - Deck refiller
Lightmine Field - Helps deal with swarm strategies
Oust - Mini tuck. If it was an instant it might be good.
Stormfront Riders - Get extra ETB effects, and protect against rift.
Artifact
Portcullis - Oppression for creatures
Arena of the Ancients - Commanders stay tapped
Voyager Staff - Easily tutorable exile till end of turn.
Prismatic Lens - Color fix and colorless ramp
Sarpadian Empires, Vol. VII -Makes a 1/1 token of a color of your choice. Works great with Spreading Plague
Juntu Stakes - Stay tapped weenies!
Nuisance Engine -
All Auriok children know the tale, "Bolgri and the Long Day of Squashing."Tsabo's Web - Stay tapped utility lands
Gemstone Array - Store excess mana and/or color fix
Guardian Idol Awkward mana rock creature
Salvaging Station - Abuse eggs and spellbombs to no end.
Silent Arbiter - Help voltron, avoid swarm,
, Profit
Vedalken Orrery - Flash for all
Pentavus - For those of us who want to pretend we're Ghave, but with flyers.
Psychogenic Probe - For punishing people who spend 1/2 the game shuffling their library.
Scythe of the Wretched - Try to avoid abusing with Triskellion
Sun Droplet - Works well in large games for recovering some of that HP back
Multicolor
Vanish into Memory - Flicker and draw/filter
Reviving Vapors - Life gain and filter top 3
Burning-Tree Shaman - Punish activated abilities
Spinal Embrace - Removal and life gain
Tsabo Tavoc - Pro legends, destroy legend
Vile Consumption - Gives creatures a life cost to keep.
Ancient Grudge - When you really hate artifacts
Unburial Rites - When reanimating once isn't enough
Damping Matrix - When you want to shut down artifacts, but not your mana rocks
Overplayed but cheap category:
Deadeye Navigator - Value on ETB effects
Conjurer's Closet - EoT Flicker Value
Myr Battlesphere - To kill Jace the Mind Sculptor (and lots of myrs and a big butt for 7.
Nevinyrral's Disk - Artifact that lets you Board wipe
Command Tower - Must have for multi-color decks
Fecundity - Lots of drawing for dead things
Wayfarer's Bauble - Rampant Growth Bauble
Blasphemous Act - When you feel like getting rid of some sticks
Eternal Witness - Too much value on a creature.
Loxodon Warhammer - Much value 1 equipment
To be finished SOON.
, Profit