We've already seen several cards that were restricted because they allowed you to tutor or reuse other restricted card
Sure, it may be fun to completely dominate the game as fast as possible, but it comes with a couple of down-sides, as it tends to get stale after a while, as well as not being as fun overall when compared to a slower and more intense game
If you are buying to open, box condition still matters for presentation, but it should not drive the entire buying decision
The power comes because whenever Field of the Dead or another land enters the battlefield under your control, if you control seven or more lands with different names, you get to create a 2/2 Zombie token
That means the market stays consistently strong, giving you plenty of opportunities to buy, hold, and resell cards for a profit