Possible Clues:

• First bid at an auction? (2 words)
• First negotiating number
• Opening quietly paper of a kind that gives the betting
• Key information for better racing tipster got wrong
• Final odds as race begins
• What's accepted, in short, by various punters
• Racing tipster provides latest information for betters
• Odds on horse at beginning of race
• Racing tipster (anag.)
• Racing tipster arranged to give the odds on a horse