Thankfully, if you dont want to spend quite this much, damaged copies are going for around $2, while lightly played examples are $3
Unfortunately, there are many ways in which opponents can remove your creature before you lose the game
Magic Arena is currently available in open beta on PC.
For instance, you only cast the room once unlocking the second door is a special game action which just happens to share the same mana cost and timing rules as casting it would
The cards that are best with Sneak attack are those with super high value EtB triggers, upon death triggers, when they attack triggers, one shot kill potential or other easily usable and super high power activated abilities
For the cost of building your deck around the restriction imposed by your commander, you get to double your mana, which is a pretty amazing payoff