Where do the prices come from and why are they different from the Exchange ones?

When you bet on Sportsbook you are betting against BAJI rather than against other BAJI customers. Therefore it is BAJI that set the prices and carry the risk.

The odds are generally higher for Singles bets (Exchange) than for the same selections in Sportsbook, but unlike the Exchange, when you place Sportsbook bets you will not pay commission on your winnings.