Have you considered the Big Money Rally as practice for the timed rallies? Since there are no real time constraints, you have days (or weeks) to evaluate several routes and compare point values and miles of each. That experience may (or may not) come in handy when on the clock.
I can testify that you get a lot of practice at visualizing the bonus and thinking, "How do I quickly get the correct picture?" That is significant, because time wasted at bonus locations seems to be a key factor in timed-rally results.
Just an opinion, from someone who isn't really motivated to do a timed rally.