Your worst enemies are static effects that give -1/-1 to creatures, but there arent a lot of ways around them other than spending your counterspells and enchantment removal
Venser also makes random other cards way stronger, like Nasty End sacrifice The Hollow to draw 3 cards for 2 mana, Vat of Rebirth gets loaded with oil as The Hollow dies, or Ringsight to give Venser skulk so we can bypass blockers while tutoring up a card
Some stores even let you trade in old cards for store credit, which might stretch your budget further
The power of these cards rests within their abilities, so you do a lot with Strionic Resonator and friends to get the most from them
In Commander, probably not a thing
This makes sense since most players are going to have decks between the Tier 3 and 4 brackets