Here is what we do in our group:
We use a rectangular block of styrofoam large enough to place our maps on (in a pinch, a cardboard box will do as well). Then we draw the maps on standard grid paper, and put it on the block.
Then we stick small, colored pins (available in any office supply store) into the map to show the location of the characters. PCs and important NPCs get pins with tiny flags with custom color schemes to both distinguish them from each other and show their facing.
All this costs a fraction of miniatures, and the only thing you loose is the visual appeal of minis. And because they take up less space, you can have maps that cover a much larger area to boot...