The maximum basic bet on Madame Mystique slots is $1,000 per round or the equivalent in BTC, ETH, or whatever currency you’re using. You may then be wondering why you’ve seen $1,250 listed as the game’s top bet amount. The answer is that this is the final max bet size when using the double chance feature, which gives you twice the odds of triggering the free spins round by upping your bet to 1.25X your current wager. So if you start your wager at the max of $1,000 and then click for the ante bet, your wager will be upped to the absolute max of this game, i.e. $1,250 on your next spin.
One small thing to point out: You cannot purchase both bonus buy options simultaneously. So if you’re using the ante bet during one round, the buy free spins feature will be disabled until that round is completed.