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.
The Idea being 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.
That said- This is one of the more advanced decks. Not really the first decks you want people learning with, but a sweet, budget deck you can use once new players are already on their feet to really knock their socks off and get them to think about something you can do in Magic that they might not have otherwise realized.
So this deck took a bit of revising to get right, and turned into a Heroic deck half by accident, but I like where it ended up. I've been trying to keep incidental +1/+1 counters out of my various teaching decks, because they're a layer of complexity that most decks are better off without in this context, but when they get rolling, +1/+1 counters feel Great to new players, so I wanted to make just one deck that properly captures this.
Maindeck Cost ~$11.40-ish at time of writing (using the blue, average values offered by the site), plus ~$2.50 for the sideboard, which is basically as cheap as sideboards get for this project, coming in around $14, nicely beneath the $15 limit.
So mostly this section is going to be notes on why I think these are good cards to learn from:
Corpsejack Menace is the fun one here, and thankfully is worded really clearly, so I'm not worried about a new player being confused about what it does.
Past that, the creature package is all cheap Heroic creatures that get +1/+1 counters, and Disowned Ancestor, who's mostly there as a blocker who can try to catch up later once all the Heroic creatures get off to the Races. The nice thing with the Heroic units is that the new player doesn't have to try to activate them- every +1/+1 counter spell in the deck targets, so as long as you're paying attention, you just chime in with a "It's ability gives it an extra counter" when they actually cast their spells, and suddenly the whole thing makes perfect sense.
Travel Preparations is going to be a primary +1/+1 counter distribution method, followed by the 2-of Reap what is Sown. Putrefy if your main removal spell, and Inspiring Call should serve as a great card advantage tool, and can save your creatures in a pinch too. Brutal in response to a boardwipe.
Abzan Charm, you'll note, does literally three all of those things, and is the best card in the deck.
Rounding out the spells is Ranger's Guile, which you can use to protect your removal-vulnerable creatures, and will give the heroic ones a counter incidentally.
Manabase is meant to be a touch lacking, but also super-budget. Look, you try to build a 3-color mana base for less than $2, it's gonna suck, alright? That's the name of the game with budget 3-color manabases.
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.
Abzan Battle Priest should serve to give most off your creatures Lifelink, which is pretty sweet against agro, and is backed up by Sheltering Word to protect important cards like it and give you more life to work with.
If you need more counters, Reap What is Sown is available, if you need more card advantage, Inspiring Call and Read the Bones should be good in value matchups. And if you want more removal, Mutant's Prey is pretty sweet here, and Plummet will hit a lot of the control wincons in these Teaching Decks, so it's actually a pretty sweet sideboard card here.
Wasn't able to make room for any artifact removal though. At least Putrefy hits Enchantments, so you have options against those.