Hi ! That's a very nice game but too easily breakable. I used the combo :
Round 1:
Double down / Flash sale / Double coupon / 10$ off / infinity round
Round 2:
Flash sale ( + Double coupon / 10$ if needed)
Round 3:
Refresh / Flash sale / Flash sale / double coupon / 10$
Because I play 4 flash sale per round, all categories are automatically deducted. I'm on round 20 with 220$ budget and cannot really lose.