Mine are actively biamped with a Marchand crossover and a Classe CA-200 (treble, mid) and a Nakamichi PA7. Active biamping is really the way to use budget amps; Maggies are very easy because of the external crossovers.
Look for an amp that doubles watts from 8 to 4 ohms. That means good high current. Don’t listen to anyone who suggests bridging an amp into your Maggies. Not a great idea with most amps to bridge into 4 ohms.
budget amps used with decent success on my Maggies:
Krell KAV 250a - doubles into 4 ohms and stays cool
Parasound A21 - also muscular
Levinson 23
i also love the Proceed HPA2 as suggested above.
Maggies are incredibly sensitive to placement and toe in angle.