I did. It used to be $10. I've tried a whole slew of different pricing options, like cheap, but time-limited, as well as price points between $4 and $10. I've found that for a simple tool, people seem to find $10 a bit off-putting. I've been running a 50% promotion recently (for over a month now) and revenue is up about 70%.
Try charging $9.95 instead of $8.00? :)