No there are lots of ways.

Look for horses with price between about $8 and $20.
Convert price to winning chance % (eg. $10 = 10%, $15 = 6.25%)
Analyse form for those horses and come up with the chance of each one winning.
Bet on any horses where chance of winning is better than the odds (eg. if horse is $10 but you estimate has 15% chance of winning then bet on that one).
If betting on TAB only bet within 30 seconds of race jump if price is still OK (allow a margin on TAB betting to allow for price change after jump).