Starting to think,because the better class of races have a more consistent type of horse,but more to the point,the variables available to analyse are easier to to comprehend,then the markets are more closely related to the starting price.
In the poor quality races,the guiding factors that influence punters possibly aren't as important as usual.Especially when there are horses with few runs.So the market tends to throw up a few long priced winners to give a bonus to people who fancy topweights.