Answer: sweetenthepot

AnswerCrossword Clue
SWEETENTHEPOTIncrease one's offer, as in negotiations
SWEETENTHEPOTUp the stakes
SWEETENTHEPOTToss in more chips
SWEETENTHEPOTThrow in more chips
SWEETENTHEPOTRaise your bet