Now that the big money game fad has passed, a decent revival can be done with a practical budget.
Winner gets $1,000 for every point between (s)he and opponent. Maybe even offer an incentive for getting 21. After all, in Blackjack, there's a bonus...so, maybe an escalating jackpot, a la Gambit, start at $2,000, increases by $500 every game. In the event of a tie game, each contestant will play their own individual question. Higher score wins, still $1,000 per point.
I liked the format of "Perfect 21," except make it $1,000/2,000/3,000/4,000/5,000/6,000 for a possible $21,000.