Answer: wannabet

AnswerCrossword Clue
WANNABET

"Care to make it interesting?"

WANNABET

"Oh, yeah?" follower

WANNABET

Offer that may be answered by "How much?"

WANNABET
Follow-up to "Oh, yeah?"
WANNABET
Words before "You're on!"
WANNABET'Care to put money on it?'
WANNABET"You think so, do you?"
WANNABET"Are you sure of that?"