Yeah, lets not forget acoustic treatment.
As far as getting a decent mix on cheap computer speakers and headphones,
there is a track on my soundcloud page(link in sig) that I mixed/mastered using cheap dell computer speakers,
and headphones, and other songs as references.
The song is titled..."Black Ops 2 Anthem"
So, if you are good at referencing, you could get by for now...
I do have studio monitors, but the mix would have been worse off due to current
room acoustics using the larger monitors.
All songs to be remixed once I am finished with my studio acoustic build for the new home.