While it's certainly possible to get lucky and double your money with a box of Masters 25 even at current box prices, which are around $180$190if your goal is to build a Modern collection, you're probably better off spending your money on newly cheap Thalias, Eidolon of the Great Revels, Blood Moons, Utopia Sprawls, and the like
Brimaz, Blight of Oreskos is a true Phrexian now, creating Incubator tokens anytime you cast a Phyrexian or artifact spell
Krark-Clan Ironworks The KCI deck had one very key weakness when it was around in Modern: it was extremely difficult to play
Jawbone Duelist Toxic and double strike is a combo of abilities begging you to be creative
Similarly, creatures that enter the battlefield attacking later in combat won't be considered when determining whether or not a creature attacked alone