Cheapest priced copy (Double Masters): $1.99 at Card Kingdom, near mint, their price list as of .
Blasphemous Act 
Sorcery · Rare · The List · #DRC-101
This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.
Legal inCommanderModernLegacyVintage
Not legal inBrawlStandardPioneerPauper
44 printings · $1.99 to $44.99 at Card Kingdom
4 rulings from Wizards of the Coast
- 10 November 2020The total cost to cast Blasphemous Act is locked in before you pay that cost. For example, if there are three creatures on the battlefield, including one you can sacrifice to add {C}, the total cost of Blasphemous Act is {5}{R}. Then you can sacrifice the creature when you activate mana abilities just before paying the cost.
- 10 November 2020To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions (such as that of Blasphemous Act). The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.
- 10 November 2020Although players may respond to Blasphemous Act once it's been cast, once it's announced, they can't respond before the cost is calculated and paid.
- 10 November 2020Blasphemous Act's ability can't reduce the total cost to cast the spell below {R}.