booster pack pokemon simulator A for (most?) sets - General TCG Simulator - The virtual

A straightforward upgrade on Spark Harvest

Alternatively you can make a threat as likely to end the game as Monger for cheaper that also does nothing else such as Phyrexian Obliterator, Master of Feasts or even just classic old Tarmogoyf

Greninja ex

Other than that, Doors of Durin can show a nice time if you play Red and Green where it bypasses the Summoning Sickness, helps you put a creature from your hand to the battlefield, tapped and attacking

Genuine bargains exist, especially for mid-range graded cards (PSA 7-8 vintage, PSA 10 modern)

After all, the variance in rarity is deliberate in terms of the distribution of cards in booster packs