Found some interesting tidbits at:
BF Best of 4 info
PART B - GENERAL RULES
1. MINIMUM BETS
The minimum total stake for any bet placed on any product via the internet is A$0.50. The minimum spend for any multiple bet placed on any product via the telephone is A$50.
2. MAXIMUM PAYOUTS
Betfair Pty Ltd reserves the right to apply maximum payouts on Tote Extra markets. The maximum payout to any one individual or entity (or group deemed to be acting on behalf of an individual or entity) on any one race, will be limited to the following:
Thoroughbred - Australia
Top Fluc - maximum to win $20,000 with the balance to be placed at Starting Price
Best of 4, Best Tote and Middle Tote Win Bets - maximum to win $50,000 with the balance to be paid at the dividend declared by SuperTAB to a maximum of $100,000
Best of 4, Best Tote and Middle Tote Place Bets -maximum to win $10,000 with the balance to be paid at the dividend declared by SuperTAB to a maximum of $40,000
Tote Plus Win Bets - maximum to win $25,000 with the balance to be paid at the dividend declared by SuperTAB to a maximum of $50,000
Tote Plus Place Bets - maximum to win $5,000 with the balance to be paid at the dividend declared by SuperTAB to a maximum of $20,000
Harness and Greyhounds - Australia
Best of 4, Best Tote and Middle Tote Win Bets- maximum to win $25,000 - with the balance to be paid at the dividend declared by SuperTAB to a maximum of $50,000
Best of 4, Best Tote and Middle Tote Place Bets- maximum to win $5,000 - with the balance to be paid at the dividend declared by SuperTAB to a maximum of $20,000
Tote Plus Win Bets - maximum to win $25,000 balance to be paid at the dividend declared by SuperTAB to a maximum of $50,000
Tote Plus Place Bets - maximum to win $5,000 balance to be paid at the dividend declared by SuperTAB to a maximum of $20,000
Multiples
The maximum multiple dividend will be 5000
The maximum payout per multi (parlay) bet is $150,000
The maximum payout per round robin bet is $250,000
3. MARKET MANIPULATION
Betfair reserves the right to void any or all wagers made by any individual or group of people acting together (or on behalf of another individual or group of people) where Betfair considers, in its absolute discretion, that such conduct is an attempt to gain financial benefit through the manipulation of tote based dividends or official starting prices. This can include persons, relatives, organisations, bookmakers and their employees
Let the games begin....