So this is a project I wanted to engage in- To make a set of 10+ super-budget 60-card decks that are simple, relatively easy to play, relatively easy to understand, and bring across the fundamentals of how Magic Works. We've since gone way past 10, with tons more in the works, and I've really enjoyed the challenge of trying to make these decks easy to play and understand, fun, and all under a $15 budget, sideboard included.
The main goal here is that you could easily build these deck for a low cost and use them as an easy introduction to how magic works, to teach a group of new players both how to play, and give them a sense of Why, a sense of what fun things they're getting into. These decks aren't gonna be particularly good, or even legal in any particular format if it stops me from including a card I think is good for the deck, but they should be fun and interesting without being too hard to get into. They should be an easily-accessible example of how fun Magic: The Gathering can be.
Ah, Illusion Tribal. And old favorite. Sadly, the card that really makes this deck rock, a clone effect that makes the clone an illusion, is outside my budget, so our Lords of the Unreal aren't going to get cloned here. Oh well, we'll just have to settle for slamming our opponents in the face with 6/6 Dragon Illusions on turn 5. What a shame.
As for budget: Maindeck cost is currently at about ~$10 (according to the middle blue numbers on this very site under estimated value), sideboard at about ~$3.80, and most of that is Polymorphist's Jest. Drop them for 2 Turn to Frog or 2 Curse of the Swine if you're less interested in the funny factor, maybe trade off one of the Psychic Barriers for it if you do, I mostly went to 3 of those because 3 copies of Jest seemed excessively pricey.
So mostly this section is going to be notes on why I think these are good cards to learn from:
The core of the deck is creatures- Lord of the Unreal is a powerful card that makes your board harder to deal with, and much more threatening. If he isn't answered, you're going to run your opponents over in no time. If he is answered, eh, you might still manage it.
The creatures benefiting from the presence of Lord of the Unreal are Phantasmal Bear, to get out early, Krovikan Mist, to fly over and hit increasingly hard as the game goes on (plus this one doesn't die to a targeted breeze or a Giant Growth).
Illusionary Servant and Phantasmal Dragon round out the roster with just some mean flying bodies that hit for a lot of damage. Sure, they die to shock, but that doesn't mean they don't sting like hell when they do connect.
Heiroglyphic Illumination lets you draw cards, or cycle it away if you don't have the time, and the counterspells are mostly for either protexting Lord of the Unreal, or countering boardwipes. You can't use them to protect your Illusions from any targeted effect, because of the order of operations, but you can counter a boardwipe, since it doesn't target, or spells targeting Lord of the Unreal or Krovikan Mist, both of which are important cards to protect. Actually, I think you could counter a Banishing Light or similar effect successfully too, since it only targets on ETB, ie after it has successfully resolved.
Oh, and Ice Cage and Singing Bell Strike are just solid Enchantment Removal effects in Blue. Singing Bell Strike I went with in particular because you should have them dead before they can afford to spend 6 mana untapping their creature.
Hey, it's mono-color, so I don't have to complain about the manabase, this is actually what you'd want from it. Neat.
As for the sideboard, this IS supposed to be a sideboard they learn how to use, to make their deck perform better in the right matchups, or just in general to customize their decks within constraints.
Psychic Barrier and Spell Pierce are for you to board in depending on what you want to counter, Runner's Bane is a good way to remove small creatures against agro, Polymorphist's Jest is just hilarious, and also a pretty effective way to remove a bunch of enemy creatures attacking or blocking. I don't think you can use it to protect your own creatures by removing their weaknesses to being targeted, even though that would be hilarious.
Halcyon Gaze if for increasing your density of threats, and Fated Infatuation seemed like a fun include, though you can only target Lord of the Unreal and Krovikan Mist with it. It's not Phantasmal Image, but it'll do.