As soon as you resolve Heliods lifelink ability targeting your Ballista (or it gains lifelink from some other source) you can shoot for an easy win, since removing a counter from the Ballista to deal damage will also lifelink for one, triggering Heliod to reload the Ballista for you
Then the spell's other effects happen
Shadowheart's Devotion Shadowheart, Dark Justiciar - $0.50 Nonfoil / $1.20 Foil Beseech the Queen - $4.10 Nonfoil / $6.60 Foil Black Market - $4.10 Nonfoil / $5.60 Foil Victimize - $0.50 Nonfoil / $0.95 Foil Ancient Bronze Dragon - $18 Nonfoil / $20 Foil Total = $27.20 Nonfoil / $34.35 Foil Shadowheart's drop is a bit better than Gale's, with higher card quality overall and one card, Ancient Bronze Dragon, almost pushing it up to the $30 mark
If you control no creatures, instead create a 4/4 colorless Scarecrow artifact creature token with vigilance
That said, at nearly $20 each, I wouldn't blame you for going with the New Capenna version
If you cant find any in your bulk bins, spending $0.20 per copy isnt too bad