Which tile cutter to use for commercial flooring tiles?
Buy yourself a steel ruler long enough for the job, and a few quick release clamps.  Just clamp the ruler and tile to a workbench and score along the ruler with a utility knife.  It's a bit slower, but for a single room, the savings is significant.

As well, you should only be cutting the edges that go against the wall.  Remove the quarter round and baseboards before you lay the tiles, and reinstall them after you're done.  This will cover any imperfections in your edge cuts.