Oh don't resist. The $100 investment to get REW-ing is hugely worthwhile in the pursuit of better sound. There is nothing as good as measuring the room and instantly seeing the results in graphic form, showing you exactly where you need to concentrate future efforts. Remember, the room is the biggest influence on the sound you hear, so that $100 investment is way, way, way more useful than thousands of dollars spent 'upgrading' amps, AVRs, DACs, BD Players etc etc. The HDMI/USB REW thread is a great place to start, along with downloading and studying Jerry's fantastic Guide to getting started (linked in his (and my) sig). Read the Guide and you'll see it isn't such a daunting task as it might at first appear.
(The $100 is the cost of a calibrated mic - REW is free)