Yes, but what about traders and arbers? That could indeed be why the big difference. Backing steamers at Betfair prices for those with live feeds etc.
In play backers as well.
All those bots that trigger a bet when a horse reaches a certain price in running etc.

__________________
RaceCensus - powerful system testing software.
Now with over 399,000 Metropolitan, Provincial and Country races!
http://www.propun.com.au/horse_raci...ng_systems.html
*RaceCensus now updated to 31/03/2024
Video overview of RaceCensus here:
http://www.youtube.com/watch?v=W821YP_b0Pg