How big is the room? That will be key in my opinion as he might over drive the Axioms to levels they can't handle well without subs (even with subs it would be possible to over drive them in a large room).
anyway...
The axioms would be a good start but I would definitely consider using them with a sub but use it wisely:
Use the speaker outs from the amp to go into the sub(s) and from the sub(s) run speaker wire to the axioms so they get the lowest octaves filtered out. The high pass speaker level crossover on a typical sub is a 1st order, 6dB/octave, at 80hz which would be just right for the axioms. They'll still be playing some music down to 40hz (and lower if they could) but it will be rolled off quite a bit so they're job is now easier. Plus the sub can be placed in the room to get the best bass and the speaekers can be pullled well out into the room for the best stereo imaging and midrange quality.
You can usually find the M3ti's for around $150-$175 on audiogon which would leave you $250 or so for a good used sub (try a B&W asw600 as it would be an excellent design).
