It sounds similar to Keno or Hot Spots in the US. A quick rule of thumb is: If the winning multiplier is >2x then it has a chance of being profitable as long as you have deep pockets. If you drop out at 4 draws, you will probably lose continuously in the long run.
For instance for CA Hot Spot here are two senarios:
Play 1 number, double your bet until it hits. If it hits after one draw, you'll net $1 because it pays 2:1. If it hits after 10 draws you'll win $1024 but your cummulative spend to that point is $1023, so you'll net $1 after those 10 games. This is due to the x2 multiplier in the winnings. Bet $1, win $2 if it hits.
Play 2 numbers, double your bet until it hits. If it hits after one draw, you'll net $7 because it pays 8:1. If it hits after 10 draws you'll win $4096 but your cummulative spend to that point is $1023, so you'll net $3073 after those 10 games (before taxes). This is due to the x8 multiplier in the winnings. Bet $1, win $8 if it hits.
Higher multiplier games NET much more and you will win IF you can stay in the game, but they are harder to keep up with because your bets increase exponentially and the numbers hit less often.
Let's say you are playing the two number game until it hits, doubling each bet.
Game 1 you are betting $1 on those two numbers
Game 5 you are betting $16 on those two numbers
Game 10 you are betting $512 on those two numbers (and you've already lost $511 in the earlier 9 games). If you hit, you'll win 8 x $512 or $4096 so you'll make all your money back and then some. However, if you lose game 10, you'll have to bet $1024 to stay in the game.
This is what I mean by deep pockets. By game 20, if you haven't won, you'll have to bet $524,288 on those two numbers to stay in the game.
At some point, betting such a large amount per game becomes unpractical.
I've found that slowing the exponential growth of bets is much more successful in 2 number games.