You'll need to wait a few turns for creatures to die before Sance Board will start producing mana
Pretty much every set has some of it and many sets have several cards
But you can also snipe a small nonland permanent, and youve paid 2 mana for this, so its an equal exchange
You actually lose card advantage by countering one of their spells with Arcane Denial as they get to draw two cards while you only draw one which this can be vary from being disasterous to being irrelevant
Cards like Conclave Mentor, Hardened Scales, and Kami of Whispered Hopes increase the number of counters you get as cards like Walking Ballista and Abzan Falconer give you ample pay-offs
Although most boxes are free from imperfections like dents, holes, or blemishes, there is a slight possibility that yours may have them