Best Cheap Amps for Magneplanar Speakers

Cheap amp and Magnepans shouldn't even be in the same sentence unless you listen at low volumes!  What volume do you listen at?  If you listen above 75db, I highly suggest a very powerful amp.

I used Ghent Audio mono amps with 3.6r and they worked wonderfully...@$1300/pr.

Nobody has mentioned Hafler?  Really?  The question is "cheap amps", right?  The Hafler DH500 is a good sounding, beefy amp and not all that hard to find.   As I write this, there's one on EBay right now, in a "Buy-it-now" for $395.  The description talks about an upgraded power supply, which certainly doesn't hurt.

On the low end, NADs are a good match, and I'll also second the Quicksilvers.

If you go tubes, the Zero Impedance autoformers might prove useful.

Adcom 555 are widely available and cheap.  New caps etc would only be a few $100.  200wpc.....

On the tube side, you can find a pr of rebuilt Dynaco MK3 for less than $1k if you are willing to take your time.  60w per monoblock of good tube power.