I owned a pair of Maggie MGIIIa speakers, the predecessor to the MG3.6. I loved them, but you need the right (preferrably large) room, and an amp with some real muscle. You really don't need a subwoofer either. If you have a large room and have the speaker placement and listening position right, you'll get plenty of bass extension. You'd be better off applying the cash to a better amplifier or front-end gear instead of a sub. I believe that the manual for the speakers even states there is no need for a sub, and that one may actually detract from the overall sound (at least the MGIIa manual stated that). I had excellent results with a Mark Levinson No. 27 (100 WPC), but would have preferred a little more power. 200 WPC would be better. You can also bi-amp these speakers, I believe. You could probably find an ML No. 23 or 23.5 in your price range on the A-gon if you're into solid state electronics. These amps would pair very nicely with the MG 3.6s.
Hope this helps and good luck!